https://www.galciv.wikia.com/wiki/Cheats_and_keyboard_shortcuts

The Wiki has a good explaination on how to do it (updated locations here for GalCiv2 Ultimate locations). I can't think of a better way to explain it. You first have to _create_ the shortcut, then alter it. That's probably why you couldn't find the shortcut.

Copy-Pasted from the link... :
You can enable cheats by creating a shortcut to GalCiv2.exe and use that to start the game.

1. Use Windows Explorer to find GalCiv2.exe, or right-click the game in Stardock Central and select Open Folder
2. Right click on GalCiv2.exe (not GC2Launch.exe) and choose create shortcut
3. Right click on the shortcut and choose properties
4. Click in the target field and hit end, then hit space followed by the word CHEAT (no switch marks necessary)

For example:

"C:\Program Files\Stardock\TotalGaming\GalCiv2Ultimate\galciv2.exe" cheat

For Dark Avatar, the shortcut should be:

"C:\Program Files\Stardock\TotalGaming\GalCiv2Ultimate\DarkAvatar\GC2DarkAvatar.exe" cheat

For Twilight of the Arnor:

"C:\Program Files\Stardock\TotalGaming\GalCiv2Ultimate\Twilight\GC2TwilightOfTheArnor.exe" cheat

Before for my old pc crashed it was working for me I just dont remember how I did it. Unless they modified the files, so it will not except the new command line.

well what you do is very simple. Open the folder in which you installed game. If you have ultimate edition you look for the file named Twilight of the Blah and use the game there to create it. If you have dread lords you do the same thing. BASICALLY DO NOT USE the launcher thingy that is in the file once you open up galciv2 go into the next folder named after your version. If you have ultimate then you will have both dread lords and twilight so just make sure your saved progress is in right folder in order for it to work. AND also it is cheat and the end NOT cheats