I'm not familiar with the figures you mention, but it would seem to me you could export what you want and re-import it to Poser, then in the Setup Room load the figure you want. Only the bones will come through and assuming the groups are the same, the teeth will work. You can delete the excess bones.

Is this what you mean? I'm really not sure. Could you clarify?

Don't forget to use the "ZBrush mode" when exporting body parts from Lightwave for Poser as OBJ, else you lose the polygon and vertex grouping data with the "new and improved" (snicker) LW OBJ export.