Change window transparency in PyGame.

Question

I want to change the transparency of a PyGame window. I don't nessicarly need to do this from PyGame as I already have an Python extension called wm_ext which controls the window which PyGame creates (it also initalizes PyGame).

So, with this extension, I've got the window handle, I just need to know how to change the window transparency on Windows and Linux (Windows looks like it might use windll.gdi32 or windll.user32).