Hello. I've given this game a go. Man is it terrible from interface to basic mechanics and script design. Awful start to the Clausewitz series. It shows how a world economic recession will affect the computer game industry in the future.
With Gnu/Linux archive manager and emacs I was able to extract the plaintext console code strings. Specifically, the RomeGame.exe v2.36c .rdata console.cpp.
fullscreen, marriages, goods, morehumans, poprevolt, courtrevolt, govrevolt, loyalty, imprison, horde, kill, fow, cash, pirate, tag, event, testcountry, and testchar. There are some others dealing with lua scripting and graphics in game state. Alot of software tech advance but, major de-evolution of gameplay since Europa I think.
'fow' is the one you're looking for. It seems to be a toggle. Most of these will require an id or argument of some form.
edit: See what you mean in your last message. Apparently, somewhere in development they disabled on/off and substituted prov_id. So, 'fow 93' will cut fow in Roma for 1 day. Honestly I think this was done to hide how ludicrous the computer opponent executes it's war plans.