[Larz]

You might be thinking of this:

http://forum.shrapnelgames.com/showthread.php?t=45908

but I've never used it and it doesn't appear to be available anymore. I use the battle sim map located here:

http://www.dom3minions.com/utilities.htm

I just edit the map file to include the units I want to test and start a game with the debug mod to get access to spells.

Debug mod: http://forum.shrapnelgames.com/showthread.php?t=36453