Drag movie and circular motion!

[URL=“http://www.kirupa.com/forum/showthread.php?t=86320”]It is possible that when i drag a movieClip to go only in a circular motion .

The thing is that i need to make a rotation button:
the button in in right corner of a square .i need that when i drag the button , the square to rotate in that direction with that angle

I had tried many thing bunt i didnt manage to solve this problem.

I think that : if make the button to move only on the imaginary circle around the square it would be easy to calculate rotation.But the circle movement is a problem too.

Any Help??

Thanks
Cosmin