This topic might be useful for your: http://ez.no/community/forum/install_configuration/win2k_ldap_server_authentication/re_win2k_ldap_server_authentication__2
See also:
http://ez.no/community/forum/install_configuration/ldap_authentication_error/re_ldap_authentication_error__3 http://home2.hit.no/~jonnybe/eZ/docs/creating_secure_authentication.pdf