1: Start Cheat Engine, then start the game. Make sure Cheat Engine has Maelstrom selected.
2: Start a Skirmish game, not sure if it would work on Campaign.
3: Once done, check the numbers on your Pop counter, like 2/20, 3/20 or how ever many units you own right now.
4: Add the first digit in the pop counter and start the search, you should get a buck load of selections.
5: Go back into the game, and begin construction on some new units, i would recommend two new units.
6: Add the first digit number again into the search engine and do a next scan. You notice it decreases, now go back into the game and do the process again.
7: Once you have done the process 2-3 times you should be left with 1 selectable answer, select it, add it in and change the value to 0.
8: Make sure you tick it as Active, and VOLA, you now have Unlimited Population.
So all you need is that, and Feedme.
Please note: If you leave the Match, make sure to untick "Active". As it may crash your game if you try to make a new Skirmish game. And just re-do it for the next match.