[Exim] Re:

Just change the $home to where ever you want it to be such as

file = /var/spool/forward/$domain/$local_part/.forward
or it could even be
file = /var/spool/forward/$domain/$local_part

an example is if the User's email address was virtualuser@???

you would have a file
/var/spool/forward/foobar.com/virtualuser