you can do this with MsgPlus!. the message helper section in the preferences
for example for counter strike i have:
/run "C:\Program Files\Valve\Steam\Steam.exe" -applaunch 240
#2#/nbusy Playing: Counter Strike: Source, Leave a message
when i type /css in a conversation window it will set my status to busy and change my name to Playing: Counter Strike: Sourcce, Leave a message
the #2# is the number of seconds it takes to change
so in your case it would be
/run "<applcation path>"
#2#/nbusy Playing COD2
note: remove the <> but keep the speech marks
/ 
