Well it's simple. You press the ~ button. A command console will open (during campaign) you type auto_win [space] followed by "defender" or "attacker" whichever side you want to win. For example:
auto_win defender

Another much used code is add_money. It works just the same, except that you'll have to specify a certain amount of money. However the command will give 40.000 max and -40.000 min.
For example:
add_money 30000
this will give the player a cash bonus of 30000.
You can also specify another faction for example:
add_money romans_julii, -20000
This will lower the AI faction's treasuy with 20000. However note that the faction names must be the internal ones, the ones used in the files. For Arche Seleukeia for example you need to use romans_julii.