I'll assume you have a button (instance name: btn) and a movie clip for your mouse (instance name: mouse_mc) on your root-timeline. The first frame of mouse_mc (framelabel: inactive ) is empty, the second one (framelabel: active ) holds your hand.png bitmap. Equip both frames with a
stop(); - action. Now, attach the following code to the appropriate frame of your root-timeline:
code:
_root.mouse_mc.swapDepths(1000);
_root.onEnterFrame = function() {
mouse_mc._x = _root._xmouse;
mouse_mc._y = _root._ymouse;
};
_root.btn.onRollOver = function() {
Mouse.hide();
_root.mouse_mc.gotoAndStop("active");
};
_root.btn.onRollOut = function() {
Mouse.show();
_root.mouse_mc.gotoAndStop("inactive");
};

Hope this helps.
aut.