Copying a section of a picture

I'm displaying an image with the picture control. What I want to be able to do, is draw a circle on the picture, then copy the data within the circle, and paste it in another picture.

Does anybody know the best way of achieving this. Any examples would be great.

Thanks
Ian

You're going to have to use bitblt api to copy the section, but bitblt copies rectangular areas so you will have to draw a circle and fade everything else into black (as a mask) and then copy it transparently