[python-win32] How to make a window client area "transparent"

[Paul Moore]

This is only vaguely a Python related question - I'm writing Python
code, but the basic issue I have is with Win32 programming regardless
of language - but I don't know a really good forum for Win32 API
technical coding questions (aside: can anyone point me to such a forum
- high signal-to-noise ratio, focus on Win32 API rather than .NET or
similar?)

What I want to achieve is client-area transparency for a window -
essentially, make the client area transparent, without the window
border, title bar, etc being transparent. I'm aware of layered windows
and alpha blending - but this affects the window border as well as the
client area, so it's not what I'm after.

Is what I'm looking for possible? If so, can anyone give me a pointer
to how to achieve it?

On a slightly related note, I know I can use SystemParametersInfo with
SPI_GETDESKWALLPAPER to get the filename of the bmp file being used as
the desktop wallpaper - but can I get the method that bitmap is used
(stretch, center or tile)? I want to replicate (part of) the desktop
in a window, and without that information, I'm a bit stuck!

Thanks, and sorry for the off-topic post.

Paul.