The comparison of the LDAP-Directories is a bit harder as it sounds.
The biggest problem is the lack of tools to do this research.
Finally i found i tool a called ldapcmp. It seems its quite old but it works under Windows XP.
1. Download the SUN LDAP C SDK (you need to register) - Platform: Windows 95 4.0 for XP
2. Extract the zip file
3. Copy the ldapcmp.exe from \tools to \lib
4. Execute the ldapcmp.exe with your parameters
The SUN LDAP C SDK also contains the useful tool ldapsearch
The available parameters can be found here