We will try to set up some automatic in-game messages (like the ones we send to announce the servers going down for maintenance) to help you better organize this event.
Just let me know the text for the messages and the desired date and time.
Unfortunately due to the approaching Easter Holidays I don't think it will be possible to have someone making manual notifications in game for this event (myself too I'll be away from Milan 25th-28th March included).
Take care,
Luca