[Exim] Unknown local users.

Hi,

I'm pretty new to Exim, and I have a question. I'm sure it's pretty
staight-forward but couldn't find it in the FAQ's.

How do I get all mail sent to my server that has an 'Unknown Local User'
delivered to one central account? i.e. if Fred Bloggs doesn't exist at
windowcleaner.com, but mail is sent to fbloggs@??? I would
like to have it delivered to another user who is going to have the
unenviable job of checking these mails.

Thanks and Regards

Steve Haigh