I'm having the same problem. none of the codes work :(
The reason the "codes" don't work is because the only cheats for Dungeon Keeper require editing the creature.txt file in the game's data folder. By editing this file, I have actually made it to where rooms are free and I get more gold. To do this, you need to scroll down to the rooms and edit the second set of numbers (Ex: scroll to ROOM_TREASURE_ROOM 2 100 200 and change 100 to 0 to make the treasure room free). Warning
: If you alter the wrong entry, you can screw up your game, so make sure to backup creature.txt before
For those that do not want to risk editing the wrong entries, I have included pictures of the creature.txt file pasted into excel so I could highlight the numbers you need to change (Also, it's easier to read when formatted as a table instead of a text document).
There's actually a cheat-menu in the game, but it has been disabled. You can use KeeperFX instead, as it has functional cheats and cheat menu's, including skipping/going back to levels, getting creatures, spawning gold, making stuff free, getting access to spells/rooms and making the map visible..