Here is a quick rundown of using the layers function in ZBrush on a posed welded mesh and transfering just the moved vertices to the unposed original mesh from the geometries folder.

First pose the figure in poser, then export the figure welded and with groups. Now check in Zbrush or other app to make sure all seams are actually welded. I have not worked with V4/M4 in a long time but if I remembe correctly they do not weld seems very well from Poser . I dont know why, I never have that problem with my own figures. Maybe zero the figure first. You may need to use a different app to weld the seems, but they must end up with the same number of vertices as the original mesh.

Use kawekis morpher to reorder the vertices to the original. Now you have a posed mesh and the original with the same vertice numbering.

Import the posed mesh into ZBrush. Go to the layers and click on new layer, now do your sculpting. Once you are done sculpting the morph, go to the layers and click on new again, you now have a second layer. Click the little eye icon next to the first layer. Now with your figure still in the scene import the unposed original mesh into ZBrush (just import not import and add) Your posed mesh will dissappear and the original mesh will be in the veiwport. Now go to the original first layer that you earlier clicked the eye icon, and click the eye icon again, and your morph will be magically tranfered to the unposed mesh, only the vertices that you moved.

I will mention that this will not solve all problems with the bend because of the way morphs are implemented in older versions of Poser, you will still need to work on it with the morph brush.

If you obtain Poser 8 you need not go through all this, Just pose your figure use the morph brush across seems and all and fix the bend as you wish, then zero the morph and Use the DP (dependent parameters) to set that morph up as a JCM. Dependent Parameters allows you to have anything with a dial controle anything else with a dial, and how much and when it starts and ends. So if you want the X-rot of the thigh to controle your morph as it bends you set the morph up to be controled by that body part, and you can delay the morph from kicking in and you can say how fast it is dialed in as the leg bends. Pretty Cool :)

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A HOMELAND FOR POSER FINALLY