Smoothing Jaggies - *Resolved*

[Illspirit]

Hey,

I am using BitBlt to draw a clock face onto a window. The clock face is a circle, and there is a mask that makes it transparent around the edge. The problem is that the background that the clock is drawn onto could be any colour or pattern, and i cant work out a way to make the thing look smooth on all backgrounds. I have tried to modify the image itself but i cant get it to look right

Ive searched the forum and most of the questions like this were not answered because speed was an issue. I dont mind any speed issues here though, seeing as though the clock face only very rarely gets re drawn, so i was wondering if anyone knew any way to do this?

Thanx,
Illspirit