Ofc you can do this as a mysql admin:
1. Login to your mysql console
2. Find the CHAR_ID of your 'victim' using
SELECT * FROM `YOURBOT_users` WHERE NICKNAME= 'YOURVICTIM'
3. Find the CHAR_ID in the LOGON table using
SELECT * FROM `YOURBOT_logon` WHERE ID= '123456789'
4. Alter in field MESSAGE text and save