Dealing utility return codes

I have an adadbs executing


ADADBS OPERCOM NOUSERABEND,LOCKU=412
/*
// IF $RC GT 0 THEN
// GOTO error1

The IF sentence try to goto to error1 in case file 412 is in use.

If I code
ADADBS OPERCOM NOUSERABEND,LOCKU=412

I get
A D A D B S: ERROR OCCURRED DURING EXECUTION:
ERROR-072, UNEXPECTED NUCLEUS RESPONSE 64
07- FILE IS USED (CANNOT BE LOCKED NOW)
A D A D B S TERMINATED DUE TO ERROR CONDITION 2013-09-26 14:37:07
11S55I LAST RETURN CODE WAS 0020

If I code
ADADBS OPERCOM LOCKU=412

I get

A D A D B S: ERROR OCCURRED DURING EXECUTION:
ERROR-072, UNEXPECTED NUCLEUS RESPONSE 64
07- FILE IS USED (CANNOT BE LOCKED NOW)
A D A D B S TERMINATED 2013-09-26 12:55:52
12:55:53 ADAI23 00001 CSHEC412 USER ABEND CODE 034

And in BOTH cases the job cancels so the IF sentence has no oportunity to do its job

How can I tell the utility not to cancel the job but only end with a return code?

TIA