You need to create a custom directory schema mapping. You can then map one of the
Basic steps:
In the DSM Explorer/control panel/Directory Integration, take the option to add a new directory.
Follow the Wizard and on step 7 select “Define New mapping”
Enter a Schema name, then scroll down and select Uniqueuserfields1 and enter “distinguishedName” in the mapping field.
Click next, flowed by cancel to not create the new directory link.
Select “Configured Directories” and then right click on your directory and take properties.
Change the schema name to the one you just created and click OK.
Go to you report and add the Directory Synchronization/User-defined/uniqueComputerField1 to your report
Run your report and you should now have the DN in your report.