Custom Shaders for DWM

Hi guys,

anybody detailed experiences with the destop window manager ?
What I want to know is whether it's possible to apply custom
pixel shaders on an application window. I know about the blur
effect which is realized with a small shader program running
on the GPU. Since all windows in vista's aero glass are DX3D
textures there should be a way to apply a shader to this texture?

MSDN on DWM does not expose such an information.
Any ideas ?

TIA
MueMeister