There are several options to set when launching Dawn of War 2 , here you can find how and what commands are available.
How To Set Steam Launch Options
1) Open Steam My Games
2) Right-click on the game you wish to add launch options to
3) Click "Launch Options"
4) Enter the launch options separated by spaces
Common Launch Options
-window - Display game in windowed mode
-forceactive - Game will run even when it does not have window focus, such as alt-tabbing away from the game
-freemouse - Mouse is not restricted to the game window when running windowed
-nosound - Disables sound
-nomovies - Disables intro movies
-novsync - Disabled VSync, can help with perormance problems
-disable32bitcheck - can resolve problems when DoW2 is crashing on Vista32bit systems
-logs - Enables error logging - This is critical when submitting bugsplat reportsnot needed anymore, the game adds this automaticly