How Do I Make The Right Arm Stay Relative To The Head?

I want to adjust the Right Shoulder so that the right arm would continuously stay relative to the head wherever it moves. And no, I don't want to weld the Right Arm to the head.

I've tried using RenderStepped + ObjectSpace, but my understanding of ObjectSpace is not deep enough for me to solve this problem. It would be easy if the Right Shoulder connects the head to the Right Arm, but it doesn't so..