Scroll bar customizatio help

Hi, I’m using a scroll bar component ( from MX) in Mx 2004. I want to customize the scroller so instead of having the default rectangle/box scroller I want to have a custom shape ( in this instance a skull)

The problem is that the skull gets stretched ( just like the square would get longer with more content in the scroll window)

Is there a way I can customise it without it stretching it?

go here
http://www.dravalanche.com/lhg/test/home.swf

to see the problem I’m talking about.