The stock game runs at 1024x768, which will fit on your displays just fine. Knight's Cross runs at 1920x1080, and you cannot fool your monitors into displaying at that resolution, and you cannot hack the d3d stuff to squish it down proportionally. That ini file is specific to the dll file. You are basically out of luck for now.
Not trying to push you into spending money, but a basic 1920x1080 monitor at NewEgg right now is $100US to $200US, with the $130-150 mark being what looks to be the sweet spot. The difficult part of a new monitor is the actual connection between your older computer and the newer monitor. If all you have is the VGA DB15 connector, then you would need a monitor with that. Same if you only have a DVI connector. One of my older cards has a VGA and a mini HDMI. Another only has VGA and DVI.