I see where you're going. Afaik you will need a bot module for this.
What can be done is..
You send "/tell xxxBot !Charlist" to open an info box with a link that sends "/tell xxxBot !Charlist add %t" when you click it.
Behind the scenes the bot would have a database where it stores current list for you (much like helpbot does with that itemslist function where you send items to it and get html back or something).
So at all times you would have a list that is linked to you only where you can add/remove characters and send out messages etc in some way, f.ex. "/tell xxxBot !Charlist message [Your Message]" which would then send out a message to everyone in your list of characters. Also, it could be nice to have something like "/tell xxxBot !Charlist clear" to empty the list i guess...
Anyway, to do this you need a bot that can do this and handles saving of character names based on who is sending commands. Like I said implementing this would be very similar to the helpbot function I can't remember the name of atm

So if someone makes a module for say vhabot or bebot or something that does this, you can add it to your guild bot and this could be a scenario:
/tell xxxBot !charlist add player1
/tell xxxBot !charlist add player2
/tell xxxBot !charlist message Congrats to you!
..
/tell xxxBot !charlist clear
..xxxBot would then send "Congrats to you!" to player1 and player2.
The downside, the message isn't coming from you, but rather from the bot

And you can't use emotes.
Hmm as i wrote this I came up with another idea that might be more powerful.
A 3rd party desktop application can be made that is running on your pc that handles everything.
By parsing the log.txt of your chat window you could actually add chars locally (and store them locally on your pc) through the chat and just run a script more like you explained when the list is complete.
Then you can do stuff like "/me hugs player1", "/me hugs player2" etc or you can send tells or whatever to everyone since the application would dynamically create scripts according to player list.
Bottom line, some coding must be done, an info box isn't gonna cut it in any of the two cases :s
Did any of this brainstorming help?
