When I did Natalia's body I created morphed versions of the front and back halves of the mesh that opened it out for planar mapping. This was done in my modeling program, simply by moving vertices and polygons. I then used UVMapper to apply a planar map to the distorted meshes, then exported the UVs and applied them to the undistorted versions. I had to go through a couple of iterations, using the trial-and-error method, to achieve a reasonably distortion-free surface. When I was happy with it I imported the mapped front and back halves into Poser and let it weld them back together.