What is the proper way to rotate or manipulate Motor6D's that are part of characters?

I am currently trying to make the rightarm raise and lower via the vertical level of the camera. I have it down, but instead of having the arm in the same position and just rotate, it moves the arm to the center of the torso and rotates. Not sure how to fix this, any ideas?

This is the line that controls it.

Chr.Torso["Right Shoulder"].C0 = CFrame.Angles(((Camera.CFrame.lookVector).unit.y),0,0)

For those who need help with the same this, you use an offset, so CFrame.new() --Where you want the arms position to be.