I found this when trying to look for a way to get WolfTeam into window mode. It works great, except you can't move the window. It just stays at the top left of your screen. All you do is put the d3d9.dll file in your Gunz folder (C:\Program Files\MAIET\Gunz) wherever Gunz.exe is and launch the game like normal from the launcher.
Download:
http://www.sendspace.com/file/x8n35r