Fancy menu

Having only done basic actionscript, I’m trying to move up in the world, and I’m having difficulty. With every other internet techology I’ve taught myself, I start by deciding what I want, then figuring out how to achieve it, but for some reason I’m on a serious mental block here. Can someone get me jumpstarted?

I need a menu with 7 graphical items:

1 2 3 4 5 6 7

where the item to the farthest left is largest in physical size. if someone clicks on, say, “5” in this example, 5 will scroll to the left, getting larger as it does so. As it scrolls to the left, 1,2,3 and 4 with drop off one at a time reappearing instantaneously in small size on the right of the menu. So, after someone has clicked “5” the menu will look like this:

5 6 7 1 2 3 4

Can’t get my head around where to start this, or how. Any thoughts, ideas, or questions?

Thanks for reading this message.