be slave ldap server

[sonjaya@stud.che.itb.ac.id]

dear all

 i have ready one ldap server running in winnt 4 + exchange + pdc , and i
just install new linux server will running ldap(openldap ) , my question
how i must set my ldap server ( openldap) be slave from ldap winnt ,or
how replication openldap.
illustration

    wint-nt (pdc +exchange) -------- openldap
           |                             |
           |                             |
     Microsoft User                  Linux User

also my plan is will use openldap for user authenthic proxy and email to.
thank's
my regard
sonjaya