Hi Juan
In T588Z, you can find similar programs -> routines invoked with indicator F (inT588Z field KENNZ). You can display T588Z, then go to print. Then filter for this character F in the Indicator field and for RP50D in Variable function part (field VINFO).
Display any of these programs that use RP50D to understand the passing of information between the routine and the dynamic actions. The RP50D structure fields are then used for inserting an infotype with the returned values in the RP50D field/s.
.br, JG