All you need to do is to activate the developer option of your game and type in the cheat codes to the SCAR console.
It will only work on Steam Edition of the Game and doesn't work on other version. It provides tons of historical skins, several new missions and enhanced campaigns.This cheat will boost and increased your fuel, ammunition, man power resources and the population cap size without using trainer program. Immersion 1944 is a - finally - Singleplayer Mod for Company of Heroes 1.
Company of Heroes: IMMERSION 1944 Early Access Real Time Strategy.