Divisional level?

While part of me is chomping at the bit to join some combat reenactment troop, I'm old enough with leg and back issues that make me think participating in the trenches might not be a great idea (let alone riding as a cavalry trooper, which really intrigues me). But I have a great historial interest in the Civil War and some theatrical background as well, so I'm wondering if there's anything out there at what might be the divisional or corps level, for instance, a division commander (who can remain off the immediate line of battle) or perhaps a staff officer to one of the generals, etc. Seems to me you wouldn't find a divisional or corps officer in a local regimental unit, so where do those guys come from? I'm in the Southern California area, if that helps anyone. Thanks for any info!