I think your best option would be to create a data file with a list of the user IDs that need to be re-enabled, then read the data file in a CL program (using DCLF & RCVF). For each of the User ID’s that you read do a CHGUSRPRF *ENABLE.
MONMSG MSGID(CPF0864) EXEC(GOTO ENDPGM)
CHGUSRPRF USRPRF(&USERID) STATUS(*ENABLED)
This assumes that you have a field called USERID in a file called USERIDS.