Hi,
Your Ztransaction must be a Module Pool(M) program, The SUBMIT statement can only be used for a Executable(1) programs.
Sessions created can be scheduled with a program 'RSBDCSUB'.
First Create Session .
You can get the Created session details in the table APQI.
Read the session details and pass to the RSBDCSUB program.
Create a Executable program and in that use SUBMIT RSBDCSUB ..... to execute the session created.
Just see the parameters to be passed with that program.
Thanks & Regards
Bala Krishna