Here is a replay from Shogun at TWC:
@Player 1
Just asked around and the two console commands you need are halt_ai and run_ai, which do exactly what the names suggest on the campaign map screen. You open the console by hitting the ~ key during play. Hope that helps!
Unfortunately, it seems that this command is disabled in console, at least in 1.2
Not like it is first time, since some other commands can only be accessed by scripts and not console.

So, I'm again stucked...