If you use steam, goto library and right click on the Galciv3 game, and you will see properties. After that, in the default General Tab, click on the launch options button. Here, type in "cheat" and this will be added to the process launch of galciv3.
For those that dont have steam, you will need to create a shortcut item of the Galciv3.exe, and then right click on it and go to properties. Notice the TARGET LINK, which has the direct path and name of the Galciv3.exe application. Here, append " cheat" to the line, thus adding this option during the process launch of galciv3.exe.