Serious Rotating Help

Hey I have a Rotating Problem…

The Script for making a Object rotate after the mouse movements should look something like this

onClipEvent (enterFrame) {
myRadians = Math.atan2(_root._ymouse-this._y, _root._xmouse-this._x);
myDegrees = Math.round((myRadians*180/Math.PI));
_root.yChange = Math.round(_root._ymouse-this._y);
_root.xChange = Math.round(_root._xmouse-this._x);
this._rotation = myDegrees+90;

Right?, i just need help to change it, so it follows a Movie clip instead of the mouse. =)