I would think that Morphing Clothes would be useful for getting the right fit before conforming, but if it is being refitted to a very different figure, the names of the body parts would have to be changed in the clothing (which I don't actually know how to do.) Also, the clothing seems to respond to not only the anatomy but also the height of the figure. What is your experience with it?

Morphing Clothes is primarily for transferring morphs from a particular figure to conforming clothes made for that particular figure. It's likely going to balk with anything that has differently named groups in it.

As far as your OP goes, there are a number of ways to convert clothing from one figure to another. The best way is to use an external 3D application, import the 3D object, make the necessary physical and group changes, then import that object back into Poser and then transfer the desired figure's rigging (skeleton) to the new clothing object. Easier said than done, I know. But, it's not particularly difficult, once you get used to it.

However, from within Poser, regardless of version (Well, anything released in the last few years.), you can transfer any rigging from anything to... just about anything. The process is fairly simple. (I only have PP2012, so there are more advanced tools for you to use in later versions.)

1. Bring the item you want to convert into the Preview Pane (Room, whatever you want to call it.. just load it up, k? :) )

2. You're going to convert this item to a prop. For myself, I export the figure's geometry as a wavefront.obj file, then reimport it. You can, however, choose to use this python script: http://d3d.sesseler.de/index.php?software=poserpython&product=figure2prop or you can go into the Cloth Room, choose the Grouping tool, then convert the figure to a prop from there. (Instructions in the Poser manual.)

3. Next, get your "prop" in the scene and load up the figure you're converting for. Make sure the figure is centered in the scene (The Figure x,y,z values are zero AND check that the figure's Hip group, or whatever main group it uses as a central rotation point, also have x,y,z values of zero. If you have to change these values in the Hip group, don't forget to recheck the x,y,z values of the Figure, as a whole, to be sure they didn't get out of whack.) You must also make sure that the figure's joint rotations are all set to zero, as well. The easiest way to do that is to go to the Window drop-down, choose "Joint Editor", select the Hip group (or central roation group/main parent) and then click the "Zero Rotations" button in the Joint Editor Menu. Once completed, you will have the figure that you're converting the clothing to centered and with all its joint-rotations at zero. This is called the "zero pose" for that figure.

(Note: If the figure comes with a Dev Version (Developer Version) using that is preferable, since it will be stripped of troublesome morph/rotation settings. Also - If the figure loads in a "posed" state, with some joint rotations at non-zero values, that shouldn't matter if the CR2 is constructed properly. But, to be safe, once you have correctly gotten the figure into a zero pose, you may wish to save this as a separate .cr2, so you can quickly call up this figure as needed and so you're sure there aren't any issues when you move into the Setup Room, later on.)

4. Using translate and scale for the Figure, move the clothing prop into an appropriate position on the figure. Use the Morph Brush and Magnets to alter the clothing so that it fits better. If the clothing is going to be too different than the figure you're converting to or if it's very complex, itself, this may not yield good results. But, if you don't have any other tools, and you want to convert this clothing, these are your options. Sorry. :( (I use a completely different process than this, so I may not be aware of any little bugs with using Magnets and keeping them on the clothing item when using the Setup room. If you encounter any issues with crashing or the like, once you enter the Setup Room, then save your alterations to the clothing prop as one Morph. That should keep the geometry in place when moving into the Setup Room. If it does not, which I don't know why it wouldn't, then simply export the morphed clothing item as a new object, with no boxes checked, then import it with no boxes checked and use it in the Setup Room, instead.)

5. Once you have the item fitted well, you can move to the Setup Room. The item does not have to fit perfectly, but it should be centered on the figure appropriately and the portions of the clothing that correspond to the figures main groups must be relatively accurate to get a "decent" fit. To move to the Setup Room, select your clothing item, then click on the Setup Room tab. It may take a minute before it loads.

6. Now, we're going to transfer the rigging of the figure you're conforming this cloth for to the cloth, itself. This process will also regroup the figure in PP2012, so I know it will also do that in 2014. (Though, you have the fitting room and such, but I know nothing about it at all.) Be sure your cloth item is in the Setup Room, then open up your Figure Library panel. Scroll down to the figure that you want to conform this cloth with. If you have a Dev Version of its CR2, use that. If not, use the zero pose CR2 you created or its original CR2, if you wish. You may have to experiment in choosing which.)  Double-click/Load the CR2 for the figure. This will transfer the figure's bones to the clothing item and setup default groups for it at the same time. (A BIG advantage over previous versions of Poser, btw.)

7. Making sure to select ONLY the "Move" tooltip, the one that looks like a "plus sign" (+), select the bones that you do not need and that do not have groups. Delete these, if you wish. DO NOT delete any bones that have a group. Poser will warn you upon exiting the Setup Room if you have done this.

8. Once you've transferred the rigging to the cloth and have deleted the bones you don't need, exit back to the Preview Pane. (Posing room, whatever..) SAVE the new clothing item, now. That way, you won't have to go through all that again, hopefully.

9. Next, load up the figure, if it's not already in the Preview Pane, and then conform the new clothing item to it. If it zips right to the figure and appears that it at least has the figure's center appropriately aligned, then your "worries" are mostly over. If it wonks off the screen, hovers above the figures head, or does anything weird, spatially, then the joint center for the main parent bone are likely off and you'll probably want to start again, making sure the figure you're creating the clothing for is zero'd properly and you have a clean CR2.

10. Now, the fun begins. Even if your cloth looks "shredded up" when conformed, as long as its center appears consistent with the figure, then the rest of it is probably due to joint zones being out of whack. Click on the "Window" tab, load up the "Joint Editor" and get to work. Start off by posing one of the figure's limb joints that corresponds to a group in the clothing. Just one. (And, throughout this process, just work on one side of the figure, as long as it's symmetrical.) Let's say you select the figure's Right Thigh bone. Rotate that bone along once axis and see how well the clothing moves. It's likely you'll have to increase the morph zones for that joint, move them a bit, or fine-tune other joint settings for that joint, with the Joint Editor open to reveal them. You won't likely actually have to change any "numbers" in the Joint Editor. You'll just use your selection tool and select the different joint zones and parameters that are now unhidden, since the Joint Tool window is now active.

Don't worry, an excellent tute by PhilC is below. Watch this to learn how to manipulate joint parameters and to fine tune your joints.

This is a series of tutorials on how to create new rigging from within Poser, from scratch. Watch these so you can know what adjustments you may need to make to your existing rigging and how to make those adjustments for the best results - https://www.youtube.com/watch?v=q8jxSOL_MAM

Note: This process will likely destroy any "morphs" that are in the clothing. That's because it resets the Groups and I don't believe, at least for versions that I have, Poser will retain those morphs using this process. Later versions of Poser may, I don't know. So, if there are any movement morphs you'd really like to keep, this process won't preserve them. It will also not preserve any "special bones", like dresshandles, in the figure. You will have to regroup those yourself and add the bones for them, manually. That's not difficult, once you get used to it.

PS - Yes, all this is drawn out and will not yield high-quality results without a heck of a lot of effort on your part. But, it will work if all you have is Poser to use and there aren't any strange issues with your figure and the clothing is actually made for something of its general phenotype. (Horses will probably not be able to easy be made to wear a bra, for instance, using this process.)  I don't use this process at all, but I have transferred some rigs with it in various Poser versions. You should also find descriptions on how to transfer rigging and how to use the Setup Room in your Poser Manual.