You can put buttons and zippers on, I would however not model the zippers with individual locks as it will kill the cloth simulator and to be honest i doubt any software out there could handle that very well.

However you have several options, either you make it part of the dress texture, which would make it possible to open and close the dress using morphs.

Another way could be to make a long chamfer box or just a box and texture that as the zipper which would give it some depth. And then use soft body in Poser to make it follow the dress dynamics. This would prevent you from open and closing the dress. 

So you could split it into two shapes one for each side with half a zipper on each.

But in either case, to make the zipper you probably need to look into bump maps and preferable normal maps. And how to use them in poser.

Normal maps in basic allow you to make a very detailed zipper which you can then transfer to a simpler shape using a normal map, and thereby get more details into it. However i havent worked a lot with this so maybe someone knows how they work in poser and if you need to do something special for them to work. 

You can see an example of what it does here:

As you can see the mesh of the character is very low res but with the normal map you get a lot more details.

http://features.cgsociety.org/newgallerycrits/g18/172618/172618_1205029919_large.jpg

"I'm hoping that if I can't set up the groups for them in advance, the least I can do is give thej the proper settings  and groups for the things to work right."

When the dress is completed the zippers should end up being part of the dress object, and the groups are saved with the dress, so if you make the zippers soft bodies and save it to your librabry they are preserved with the dress everytime you load it in a scene. 

I would suggest that you start just by making a very simple button and test how it works in poser with the soft body, so you get a very good idea how to handle the zipper, as i would expect it to give you some problems, if not a lot, as its not the most easy thing to get to work i think.