you can not run two clients in one pc, cause of program-access reasons. (if i would allow that, the program would crash!) you have to have 2 pc's. sorry.
This uses "Myrddraal's script" too. but it does everything automatically, so you dont need to manage a thing (like changing textfiles, autoload, start rome, end turn, transfering savegames). i designed this program to play in LAN or over the Internet and directly, if everybody is online and sit in front of his pc.
battles are fought against the AI. thats okay i think, cause if everybody fight against the AI, its fair.
I played the campaign with my brother and it works perfectly. but it takes a long time to do that. one week (3-6 hours per day) or more with 2 players to kick the other out. but therefor you can save the game...