I still don't know how to use "Stadium_0", "Stadium_1", etc, but somehow I figured it out with other settinghs. Now every year my Croatian Supercup is played abroad, in cities where there are big communities of Croatian diaspora, just like I wanted. Not that the game knows that, but it gives me a sort of a personal satisfaction, that in fiction atleast, Croatian emigrants are enjoying watching two of the Croatian top clubs Cheers!