Chain two openLdap Directories

["Eudes LEDUCQ" <LEDUCQ@hec.fr>]

Hi,
 
I have a problem. I have two openldap Directories. The tree structure
of the two directories is very different (first: dc=xx,dc=yy and the
second o=xx,o=yy) . I need to chain the two directories. In the first
step I have created a referral link. (I use ldap Browser to watch me
directory) So i use a user to connect to my directory
(cn=Manager,dc=xx,dc=yy). But this user don't exist in the second
directory. So referral link seam no to work.
 
so is some one can help me ?
 
is it possible to chain the two directories ? (I use berkeley database
for one and ldap for the second). 
 
thx.