You can try. Except the rest of the song tends to rule out any possibility of it being German. That, and the fact that it is, genuinely, a good song would preclude it as well... Seriously though. Has there been a theme song that has made it to the terraces? And is still there to this day?
Re: Forca Portugal That was a pretty cool song and I think people reacted to it. Whenever it was played in the stadium before a game -- whether or not Portugal was playing -- everyone would suddenly get energized and start waving their flags or scarves. You also heard it on the radio a decent amount.
Dario G - Carnival De Paris Not sure if was an official tune for 1998. But that's all you heard through that hazy summer...
Not a theme song, but Macka B from Jamaica had a dancehall hit about the Cameroon team from Italia 90 WC, BAM BAM Cameroon.