Message Processing

I *think* the reason I don't like message processing is because I'm
stoopid. Here's my deal...PGMA calls PGMB. PGMB does a bunch of stuff,
but eventually sends a message to PGMA. PGMA is RPG, PGMB is a command
called by QCMDEXC. If I display the message details of the message I
want to receive (viewed through my job log), it has the correct from
program and to program. I want to use the QMHRCVPM (Receive Program
Message) API to get that message, parse it, and do something based on
the contents. When I make the call to QMHRCVPM, it executes but returns
nothing. I'm using *ANY for the message type (tried *COMP but that
didn't work), *EXT for the call stack entry (tried * but that didn't
work).

Please...tell me what I'm doing wrong. All I can offer is the ability to
feel smarter than me. Not much, but it's better than a sharp stick in
the eye.

TIA...