you dont say what your modeling in so this may NOT apply(blender does wink wink )

make low(ish) poly dress, uv map it, duplicate it and add a level or two of subD, add wrinkles then bake a displacment map to the low poly one, so all you have to do in poser is run the sim on the low poly then add the map, it should work (I think) but never tried it yet!!!! (only just looking at blenders baking abilites)

will try it out and let you know if it works