We eventually worked out that you have to set up a user on
your network, and set up an email account for them in
Exchange. You then have to log in as "The projector" for
instance and grant calendar permissions to those who will
use it - so Default user I guess in most cases. Then set
delegate permissions so that someone who is nominated can
open and use the account within their own calendar. It's
working quite well for us now - couldn't find any how to's
on the Microsoft site - so we just thrashed through it!!