Call Message Queue or Program Message Queue?

Does each level in the call stack have its own message queue
associated with it? For example, I have the following call stack entries:

IMLFEXTR FIX0460LFI _QRNP_PEP_IMLFEXTR
IMLFEXTR FIX0460LFI 13400 IMLFEXTR
IMLFEXTR FIX0460LFI 30900 GENERATEEXTENSIONREPORT
IMLFEXTR FIX0460LFI 49400 PROCESSITEMEXTENSION

I also have an RPG MONITOR set up to trap an error. In the
ON-ERROR, if I execute the following API then it does what I want it to do
-- which is to remove the error message from the joblog.

callp IBMAPI_RecvPgmMsg( QMHM020000: %len(QMHM020000)
: 'RCVM0200': '*': *zero: '*LAST'
: *blank: *zero: '*REMOVE': ApiErrC );

But, I created a service procedure so that this API call does not
have to be replicated all over the place. In that service procedure, I
dynamically determine the calling program (using another service procedure
I created) and then issue the above API as follows:

callp IBMAPI_RecvPgmMsg( iMsgRcvr: iMsgRLen: iMsgFmt
: iCaller: *zero: '*LAST': *blank
: *zero: '*REMOVE': ApiErrC );

I ran it through debug to confirm that iCaller contains the
expected calling program name -- and it does. In this case, though, the
API does not do what I want -- no errors are raised, but the error message
remains in the joblog. Thus, my original question.

Sincerely,

Dave Clark