How to parent an object the parent of a bone/how to make a bone follow the mouse

For my project I want my characters hand to point where the mouse is. I made an IK setup for that arm and so now when I move the IK bone by the wrist it moves and bends the arm as it should.

My initial plan to make the bone point at the mouse cursor was to set a sphere as the parent of the ik bone and then just move the sphere to the mouse coordinates when it was moved. However, I just found out that I can make a bone the parent of an object but not an object the parent of the bone. Is there any way around this so that I can make a sphere the parent of the IK bone or instead an alternative idea anyone has?


Edit: Sorry forgot to attach the file: File