http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3443915&ebot_calc_page#message_3443915

In this thread I describe an approach to not only replacing body parts, but grafting in entire new bone systems and using the objFIleGeom call to access the new geometries. There is a LOT more that can be done with this than what i think people normally delve into. -Les