[exim] mail forwarding problem

I've got a Linux FC1 box running cPanel and exim which I administer
remotely.

After a disaster, the box was brought back to a virgin state, and we're
gradually bringing various services back on line.

It looks like I can happily receive mail, and I've just succeeded in
sending mail from the box.

What I would like to do is setup very simple forwarding. If our domain
is @mydomain.com, and I have various address like
techsupport@???, or jokes@??? I want all jokes
forwarded to a group of 5 people (censors if you like :-) ) these people
have addresses like joe@???, mary@???.

I used to be able to do this with a few mouse clicks with cPanel, but
this doesn't seem to work.

It occurs to me that a configuration file/directory has a permissions
problem, but I can't reach first base on the stuff I'm reading on the
web. Much of it refers to a .forward file in the user's home directory,
but there isn't a user 'jokes' or 'techsupport', so I must configure
this somewhere else.