Shutting down a thread after a specific number of messages

I wrote a tcl proc that counts 3 messages then shuts down the thread once the third message has gone through.  The problem is the proc only works on the inbound tab (Send OK Procs) of the thread that I’m shutting down and it ends up shutting down the thread befoe the messages is completely through.  If I place the proc on the outbound tab of the thread in “TPS Outbound Data” or “Send OK Procs” it does nothing.

Has anyone sucessfully written a proc to shutdown a thread after a certain number of messages has gone through?