Minimize Window with Key

[Stefan Heinemann]

Hi

Is there a possibility to minimize a window
of a game like quake3 or armyops in
xfce 4.0.6? 
Maybe something like the key combination
windows-d in Windows?

It is possible to change to the window mode
of the game, but I dont know how I can get the
control over xfce....

Greez
Stefan Heinemann