Aero glass effects for part of window

[Jens Müller]

Hello,

I like to have my window backgound with a Aero glass effect, while the real
content of the window is enclosed in a rounded rectangle which should be
opaque.

I tired the following to achieve the effect:
Use of DwmExtendFrameIntoClientArea to have the glass effects where the
backgorund is black, however if I draw a rounded rectangle for my content,
this is also nearly transparent, even if it is not black. Also other
controls paced on the window are partly transaprent, the more black they
are.

Use of DwmEnableBlurBehindWindow. Even if I specify the region by usign the
client area and cutting out the rounded rectangle, the areas not belinging
to the region are displayed completely transparently.

Any idea how tis can be done?

Thanks!