Hello to you. I have a one GOOD question about RTW-BI.

Is it posible to create a "custom battle" in the "single player" that models a Sortie from the besieged castle? Maybe some command line parametrs, or else low-level things? I need to create battle, where the castle masters will be Attackers, but not Defenders.
If I can do it on the global map, why can't i make it in customising?

Precise answer i can't find at the all internet...