Ron,
Did we have a conversation about this when the Bonanza released?
Here are the magneto increase/decrease events I put together for FSUIPC for the Bonanza; I looked and the Commander Lvar looks to be the same. I remember testing these with the Bonanza, and I don't see why they shouldn't work with the Commander, however I have a button box with a key switch that I have bound to the individual positions, so I don't actively use this.
BT36_Magneto_Increase#(L:BKSQ_IgnitionPosition_1, number) ++ 4 == if{ 5 (>L:BKSQ_IgnitionPosition_1, number) } els{ (L:BKSQ_IgnitionPosition_1, number) ++ 5 min (>L:BKSQ_IgnitionPosition_1, number) }
BT36_Magneto_Decrease#(L:BKSQ_IgnitionPosition_1, number) -- 0 max (>L:BKSQ_IgnitionPosition_1, number)
Calling Magneto_Increase should increment the L:BKSQ_IgnitionPosition_1 LVar by 1 and max out at 5 (start), and Magneto_Decrease should decrement it by 1 to a minimum of 0.
Drop the two of them into myevents.txt and reload your presets, you should be able to bind them to something and give them a whirl.