[exim] Address rewriting based on an LDAP query

Hi all.

I was wondering if Exim can be configured to use LDAP for recipient lookups?

It is crucial that I be able to rewrite the addressed based on
information supplied
in the search DN and the output of the LDAP query.

For example:

I want to be able to address a message to "someone@testdomain" in the
RCPT TO command.
I would like the LDAP search DN to be based on the handle in the above
address.

The LDAP server will only return the hostname of the box where the
recipient mailbox is located.

I would like the address used in the RCPT TO command to be rewritten
based on information in the original RCPT TO command, and also from the
output of the LDAP search.

For example, if the user is found, hostA is returned in the query.

I would like Exim to take the handle supplied in the original RCPT TO
command, append the @ sign, followed by the output of the LDAP search,
followed by the domain supplied as part of the original RCPT TO command.

Is this possible????