Well I did solve this for my January Game Jam and the answer is that the attachment point has to be simulating physics in some respects. Fortunately, animated skeletal meshes fit this category just enough to trick the system into doing our bidding.
So you can’t have a moving attachment point linked to a code driven moving static mesh, but you can certainly do it with an animated skeletal mesh.
I’m not sure if you can attach a dummy skeletal mesh to a static mesh though.