How to keep a bone in place when posing/animating

I’m new to animating in Blender and trying to figure out how to keep a bone in place (pin?) while posing for animation. My character is a monkey swinging vertically across a ledge of a wall. I want to keep the hand completely still, in place, while rotating the rest of the body from the arm. But every time I try, the hand moves along with the rest of the body. Is there some way to pin the hand in place during animation? Thanks in advance!

For some reason Auto IK didn’t work, the hand kept moving with the arm. But I did set up a proper IK chain from the hand down to the body and that worked. Thanks for taking the time to respond, I do appreciate it!