http://www.msgplus.net/help_cmdtag.php
if you want to keep it in 1 command:
/naway <status nametag>
/nbusy <status nametag>
/nonphone <status nametag>
/nlunch <status nametag>
/nbrb <status nametag>
eg: /nbusy working
otherwise, make a personalised status and call it by /persostat <status number>