Assign verts to body

I want to have multiple boxshapes do the collision for an object. How can I assign specific vertices (i know how to get at that data in OGRE) in a mesh to be controlled by a certain body? Something akin to skinning, i believe

I could do it by rigging the mesh with bones and then updating their positions to match with the body's positions, but I was hoping to do it more directly with physX. Anyway to assign vertices, or at least create meshes that share vertices with other meshes?

The nearest I think to that is a collection of convexShapes, probably rigged together by joints.