Retrieving Command like F9

I have a need in a CL program to capture the complete command that was entered 
to execute the CL program.  What I think I am looking
for is a way to programmatically "press F9" and capture the result.  I cannot 
find any interface to do this .... is it possible?
Some obscure API maybe?

A bit more information ... there is a command definition for this CL program 
that includes prompting for optional operands.  The
user enters the command name and is prompted for the other operands; in the job 
log only the "originally" entered operands are
present; those that were optional are not in the job log, so since F9 uses the 
joblog to retrieve previous command, it seems F9
would not retrieve all operands, however, this seems to be in conflict with 
normal interactive operation.  For this specific case:
operator enters "T1 DEVICE(TAP02)" and is prompted for OPTION.  Joblog shows 
"T1 DEVICE(TAP02)" but as CL program begins it is with
"T1 DEVICE(TAP02) OPTION(A)" because operator was prompted for OPTION and 
filled it in.

Thanks for any advice ... Chester Hood