You can use Hyperlobby, or Hamachi to play in a virtual LAN (I prefer the second option). The coop mode run only if you eliminate the S.e.5a from object/aircraft folder (I don't know why...). I search players for multip...so if you want I'm here
I play FE with Hamachi (only 2 players). When I make a dogfight it's ok, but the co-op don't go (the game crash). It's a nonsense that there are problem only with co-op and not with dogfight... somebody can help me?