Each client profile can have a separate MOTD or Message of the Day .
APPEND - Add a line to the bottom of the motd.
DEL - Delete a specific line.
ERASE - Erase the entire motd.
INSERT - Insert a line into the motd.
LIST - List the motd
/as help client motd <command>
These commands should give you the flexibility to easily customize your motds. The motd commands work the same way that the chan greeting commands and the script commands.