at the beginning of each scenario file (or saved game) there are some lines, like this:
war = {
id = { type = 9430 id = 1 }
attackers = {
id = { type = 9430 id = 2 }
participant = { ITA }
}
defenders = {
id = { type = 9430 id = 3 }
participant = { ETH }
}
}
war = {
id = { type = 9430 id = 4 }
attackers = {
id = { type = 9430 id = 5 }
participant = { CHC }
}
defenders = {
id = { type = 9430 id = 6 }
participant = { CHI }
}
}
Just follow the model