>>2840932Several methods exist.
1. A vertex morph can be used, but good luck making it actually controllable and pretty if the area it covers has the physics of a regular skirt. (Vertices deviating from the original position deform wildly.)
2. Assuming you're trying to move a part affected by physics, bake the physics (MMM, Blender, NexGiMa) or just turn them off if it's a standalone render, then position the physical bones however you want. Parenting the hand is pointless, by the way. The reverse would make more sense.
3. You can always make use of movable bones, whether they have physics linked to their bone tracking rigids via joints or not. This is how I avoided wing clipping for pic related and made Flanny fold her wings. Note: physics won't move without a bone tracking rigid they attach to.
4. Lastly, there's the plugin used by the author of
https://www.nicovideo.jp/watch/sm42539554:
https://seiga.nicovideo.jp/seiga/im7778347I think it essentially batches method 3 (note) by creating a movable duplicate for each physical bone, but I haven't used it, unlike the other three methods.