Quote Originally Posted by Moros
No, that's impossible. There's a script that can change faction, so you can e-mail him the savegame, he runs the script, plays with his faction sends it back you run the script play a turn as your faction,... However your battles ofcourse can't be played against the other human player etc...

Note that this isn't a project of EB or anything. I don't even knwo if it works with 1.5 and or EB. I don't even know if it's finalized. But you can do a search and try.
This script was done by Myrdraal back in 2005. He once tried to organice a multiplayer campaign, but it took ages to start (mostly because some want to play with a light RTR mod which took ages to complete). When the campaign finally started we had to struggle through members who disappeard and some who never showed up. After almost half ayear of waiting i could then finally do my first turn (as the new leader of the mighty dacians) but somehow it was th last turn for this campaign and i was only fifth in a list of 20. Most players had vanished, the ones who had stayed that long (me, and i remember shifty was still there, too ) gave it up, too.