Naja, eigentlich sollte das schon gehen:
WS_EX_NOACTIVATE
Windows 2000/XP: A top-level window created with this style does not become the foreground window when the user clicks it. The system does not bring this window to the foreground when the user minimizes or closes the foreground window.
To activate the window, use the SetActiveWindow or SetForegroundWindow function.
Aber das funktioniert leider nicht
Gruß
Jörg