[Exim] rewite of addresses.

Good morning all.

I have the following:
######################################################################
#                      REWRITE CONFIGURATION                         #
######################################################################

begin rewrite
*@dsearch;/usr/exim/alias-file/    ${lookup{$0}partial-lsearch\
                        {/usr/exim/alias-file/$domain}{$value}fail} ET

The alias-file directory has a list of domains.
each domain file has a list of users and rewrites as below:

user        user@???

The abovementioned lines do not work.

However, the line below does BUT tries to rewrite ALL mail entering.
This is failing and causing my log file to fill up with failed messages.

*@* $1@${lookup{$2}lsearch{/usr/exim/alias-file/$domain}{$value}fail} hT

any ideas?

Regards,
Tom Kinghorn