Managing Open Directory based ObjectClasses from 389 Directory Server interface

Question

I want to produce a coherent directory services platform for every of MacOSX, Linux, Windows and Solaris based workstations. The LDAP implementation I use is 389 Directory Server. Authentication worked (with some struggle) on all platforms. But what I really want is to get all the ObjectClasses from Open Directory that differ from original LDAP schema to my DS Schema. Is there any other way to manage those classes than simply modifying the 389 DS Schema to implement them and then edit the attributes in the entities manually ?