Integration of foreign domains

[Kevin Thorpe]

Hi, I'm stuck with foreign domain integration and not sure how to proceed.

We have our own LDAP domain (dc=<domain>,dc=com) and within it two
sections, ou=staff (us) and ou=People (clients). This works just fine and a
search on dc=domain,dc=com covers both sets of users as website logins.

Now I want to add in users from a client's LDAP server. I can add a new
domain (o=<client>,c=com) and attach it to their LDAP server and that
looks like it's working just fine, but how do I attach my website to this
setup?
I don't see how I can look up users across multiple domains.

What I think I need is to pull in a single branch of their domain into our
domain.
That would look something like:
dc=<domain>,dc=com
       ou=Staff
       ou=People
       ou=<Client>        <====  ou=Utilisateurs,o=<client>,c=com
but of course I'd still need to relay any bind requests in the ou=Client
section
to the client's LDAP server.

Can anyone point me in the right direction please?
NOTE: values in angle brackets are simply anonymised.