[Samba] multiple ldap branches

[Alan Silver]

All:

I have a samba server running on centos 6. samba version 3.5.10

I would like to authenticate against my ldap sever (openldap 2.3.43 on 
centos 5.8).
I have this set up just fine on some of the samba servers that I am 
running.

I am trying to bring a new samba server online that points to users on 
different branches of my ldap server.
So, something like
ou=People,ou=internal,dc=chem,dc=wisc,dc=edu
ou=People,ou=external,dc=chem,dc=wisc,dc=edu

What is the method for setting up the samba to point to both these 
branches for authentication?

Thanks much

alan