I would recommend watching the YouTube from a fellow named Tony Vilters.

He described in great detail how to handle poser geometry, exporting it from Poser to Blender, sculpting HD morphs and backe them onto the original geometry in Poser by using the morph brush tool. Very informative stuff, unfortunately the guy has vanished, but he was kind enough not to delete his videos or pull his channel entirely. The channel name is Tony Vilters.