I don't know if this will help you any, since I don't know what RTI or AMX accepts, but the code you listed basically says it is using NEC protocol (I only know this since when IR codes are given in that format and not specifically mention the protocol, it usually means NEC protocol). The first group of numbers (50AF) is the device code, and the second group is the command code. You can essentially ignore the second half each group (ie AF in 50AF, and C1 in 3EC1), since they are just the hexadecimal compliment of the first half (FF-50=AF). So for POWER ON, it would be device number 80 and command code 62.

If Pronto hex code would be more useful to you, you can use Makehex or some other conversion program to generate the hex codes with the information you have.