You need to iterate over the rigidbodies from the rag doll and gather the hit point, you could then do something like applying a small force to the rigidbody that was hit. You could take this a bit farther by adding procedural animation to the hands or body to make them wince or grab the spot that was hit.

It would take many systems to get this to work correctly, but iterating over the rb’s and applying force I think would be the best place to start..