Arm rig advice

Hello. I’m trying to rig a deformer into a arm. I’ve moved the pivot for both the drawing layer and the peg but cannot move the one centre of screen.
(See attached images.)

Any help would be much appreciated.

Hold off on all the responses everyone. i figured it out myself.

I didn’t have a solution but I would like to know what you figured out as would other people if anyone else encounters something like your problem. It would help in understanding how the software works to understand what could cause that situation.