Stationary QB question

[Vince148]

I can't find anything in the Dixie rules that really addresses how they can be/are used.

Can they be used during a run play? For example. Can I start with a stationary QB, snap the ball, and then replace the stationary QB with a running QB?

Can a running QB even replace a stationary QB or are stationary QBs only allowed to be switched on passing plays at the time of the pass with TTQB?

Can someone clarify this in regards to Dixie rules please.

Thanks.