New formation

[Cesco]

I would like to create a new formation, wich files do i have to work on?
To be more specific, i want to make a formation where soldiers move backwards, a feature that, for some reason, doesn't exist in any tw games...so, i guess, i have to somehow "connect" the proper animation to the new formation. Is that possible? If it is, how to do that?
i think that this kind of formation could give a more deep tactical feel to the game, with more importance on reserve forces.

[Cesco]

Nobody?