@Andy I see; well currently Pham is the only bot (in this room) I know of that uses >> to signify a command (unless you plan on adding commands to your bot, if you do, I can always change mine quite easily).
I have an idea. How about: post message -> get message ID by searching for message with X content -> add ID to list (if message is found) -> if a message is a reply and starts with any of the IDs in your list, execute command?