Default or wildcard virtual user with exim?

[John R. Ackermann N8UR]

I have a simple virtual user mail setup using exim 3 on a Debian testing 
box.  I have a director like so:

virtuals:
 driver = aliasfile
 domains = /etc/mail/virtuals
 file = /etc/mail/virtual-aliases
 search_type = lsearch
 include_domain
 no_more
and this works fine for the named mappings in the virtual-aliases file.
However, I'm getting a lot of frozen messages that are aimed at other, 
non-existent addresses in the aliased domains.  For example, 
"[EMAIL PROTECTED]".  These are probably spam messages, but I'd like the 
domain owners to deal with them rather than me.

I'd like to be able to do something like:
# virtual                               real
[EMAIL PROTECTED]               [EMAIL PROTECTED]
[EMAIL PROTECTED]               [EMAIL PROTECTED]
[EMAIL PROTECTED]               [EMAIL PROTECTED]
I've tried this syntax and it doesn't work with the director defined above. 
Is there a way to implement this kind of mapping?

Thanks,
John