Program CAJCCMD0 is the Scheduler Tracking Command Interface.
Call to Scheduler CAJCCMD0 defaults to the subsystem id of SCHD. How to dynamically call a different Scheduler subsystem id?
If using a different subsystem id, for example SCHX, a dynamic allocation of the $$SCHX DDNAME to DUMMY must be done prior to the call to CAJCCMD0 program. Use the DYNALLOC (SVC 99) or the BPXWDYN service for the allocation.
Scheduler Systems Programmer Guide Chapter 7 User Exits and APIs