Poser's grouping tool can probably do what you want. That's the button that looks like a square with a dot in the center. Select one of the body parts then open the Grouping tool. Everything will turn black except whatever is selected. On the group tool there's a button [Create Prop] that will create a prop from whatever's highlighted red. The spawn props button will create a prop from every group in the selected object. That might be handy if you imported the original OBJ geometry file from the set. Then you could spawn all the props at once.

Anyway, once you've spawned whatever prop you needed from the original just save that prop to your library and you can reuse it whenever you want to.