Stick left hand to weapon sway rotation.

Hi guys,

How to make a FPS left hand rotation that will follow weapon sway? Because right now, my weapon is rolling right and left but left hand is staying still because its attached straight forward to gun socket. Any thoughts?

I have no idea how to remove this big heart, sorry :D.

I figured it out by using IK bones in Anim graph of skeletal mesh of player hands :).