You don't have to map the morph targets, just the object itself. Poser uses the morphs as a comparison for sizing and placement, not for UV coordinates. If you remap the hair, you should be able to import it and have it sit as normal on Posette's head. You can always cheat and hack open the .hr2 file, change all instances of the original .obj name with the new, remapped .obj, and save it under a different name. Then copy the original .rsr and give it the same name as the new .hr2 so you have a thumbnail as well.