Put it in your /home/irlp/custom/ directory.  Make it executable (chmod 755 /home/irlp/custom/star69) and edit the, "user configurable settings" near the top if you want to have it take advantage of an AUX line PTT enabled node.  Otherwise there's nothing that needs to be configured in the script itself.  Simply add the following lines to your /home/irlp/custom/custom_decode file to be able to invoke it from your DTMF keypad:

 # call star69 script
if [ "$1" = "S69" ]; then
    $CUSTOM/star69 & >&/dev/null 2>&1
    exit 1
fi

This would cause the DTMF sequence, "*69" to call the star69 script.  Enjoy!