Probiers mal so (ohne Gewähr):

Code:
D CheckCode       PR                  EXTPGM('CHKCD01R')
D P1                                  LIKE(CHK03R) CONST
D P2                                  LIKE(RC)
D
D CHK03R          DS            50    INZ            
D  PaSL3                  1      2  0                
D  PaCD3                  3      5                   
D  PaBZ3                  6     30                   
D  PaKB3                 31     35                   

D RC              S              1

 /free                          
  callp(e) CheckCode(CHK03R:RC);
  eval *inlr = *on;
 /end-free