Help needed from the actionscript gurus

Hy friends.

I need help from one of the guru’s of flash. I am working on my website and I want to create something nice and usefull. Unfortunately I do not know how to do it. I didn’t find any tutorial online for this.

Here is what I want to do. Please visit first the link below so you can understand more easy what I need.
[COLOR=#800080]http://oakley.com/pd/1146[/COLOR] then click on the tab LENSE TINT below the product. There is a slider that demonstrates the polarized filter of the sungrasses.

Is exacly what I need. I will have a cube for example and I need a slider that will say on it Gragg me! (interactivity with the visitors) when the visitor draggs the slider I need another image, masked to the shape of the cube, to cover the cube shape. Something like a before and after action but controlled by that slider. If cannot be masked only to the cube it can also be a full square. I will create the 2 or 3 images with the same background but different cover for the cube.

that’s it. Easy at the first look but hard for me to do it.

Thank you