16:10 Resolutions?

[Space Cowboy]

Hello, I have a 16:10 monitor with a native resolution of 1680x1050. Needless to say like with every monitor the picture looks a bit washed out outside of the native resolution. Unfortunately there seem to be only 16:9 resolutions available. So, is there a way to set the game to 1680x1050 with a 16:10 aspect ratio in an ini file or with a commandline parameter.