Knowing who answered a call..?

[J. G.]

Hey gang,
I have a nice AGI script that records a call via MixMonitor after doing some
database lookup.  What I am not figuring out is how to tell what extension
answered the call after it was handed off to a queue.

                $AGI->exec('MixMonitor',$fileName . '|b');
                $AGI->exec('Queue','TestQueue');
               * my $ExtThatAnsweredTheQueueCall = ?;*

I want to then append the extension that answered into the $fileName, which
is easy enough once I figure out who answered the queue call.

Any ideas?

Thanks!
PB