Armature pivot thingy

This is pretty hard to explain, but is there a war to kind of transfer the movement from a bone to another, which the pivots around a point? I made a drawing that probably helps.


If i understand what you need. A ik with a target will work. Is this what you want? http://www.pasteall.org/blend/23472

Ah dude this is just what i wanted! Thank you so much!