question about my upgrade chances on UA ticket on Lufthansa (UA 8879 DEN-FRA)

Available Cabins: F4, A4, J4, C4, D4, Z0, P0, Y7, B7, M7, U7, H7, Q7, V7, W7, S7, T7, L0, K0

I don't see any 'R' - is there another cabin I should be looking at?

I am in business on a C class fare, and got the paper upgrade certificate mailed to me. Do I have any chance at getting the upgrade to First based on the wacky letters / numbers above?

Thanks for the help