If you exported it out of Poser, no matter what, it will combine into a single mesh when you bring it back in. For some reason, when you export a mesh out of Poser, it divided the mesh according to the grouping, at least in Wings 3D. I am not sure about Blender or other 3D apps, but in Wings, it imports divided with the grouping.

If I had a nickle for ever time a woman told me to get lost, I could buy Manhattan.