It is my understanding that you could write a simple tclproc to parse out the trixid data. Here is a simple example from the Level 2 class.
trxFrl.tcl
######################################################################
# Name: trxFrl
# Purpose:
# UPoC type: trxid
# Args: msgId = message handle
# Returns: The message’s transaction ID
#
# Notes:
# The message is both modify- and destroy-locked — attempts to modify
# or destroy it will error out.
#
proc trxFrl { mh } {
set trxId trxid ;# determine the trxid
set msg [msgget $mh]
set transType [string range $msg 8 13]
echo Transaction Type: $transType
return $trxId ;# return it
}
Then, whatever is returned by $trxId is the value(s) used for routing.