Firstly, this should be in MsgPlus! General Chat.
Secondly: This would be very hard to do, if not impossible because custom emote.s aren't transfered until the chat window and different ppl have different shortcuts (e.g.
![:happy:](images/smilies/xso_smiley.gif)
could be a cusom
![:D](images/smilies/msn_grin.gif)
for one person and
![:|](images/smilies/msn_disappointed.gif)
for another
![:P](images/smilies/msn_tongue.gif)
). Also, I don't think protocal allows for this kind of thing.