Is this a Program Interface job or File Interface? I believe there is a UNICNUM member in the SRCELIB that you can modify to add the century to the cycle.
* THE USER MAY ADD CODE HERE TO MODIFY THE CYCLE NUMBER -
* FOR ACR PROCESSING. THE CNUM AREA IN LINKAGE IS PROVIDED -
* FOR THAT PURPOSE. -
* -
* RELEASE 2.0 -
* REMARKS. UNCOMMENT THE CODE BELOW TO INSERT -
* THE CENTURY INTO ALL CYCLES. -
*---------------------------------------------------------------
* IF CNUM-CYC-DT IS GREATER THAN ZERO
* AND CNUM-CC IS EQUAL TO ZERO
* IF CNUM-YY IS LESS THAN 80
* MOVE '20' TO CNUM-CC
* ELSE
* MOVE '19' TO CNUM-CC.
GOBACK.
If it is file interface, it could be the way the format when the cycle is being picked up.