If like me you have a few RGS workflows it can be tedious finding the DN of the RGS object.
Powershell to the rescue!
Use the following cmdlet to find the DN of the object for ADSIEdit as the GUID in get-rgsworkflow is totally unrelated.
Get-CsApplicationEndpoint | where {$_.displayname -eq "Example Workflow"}
Where “Example Workflow” is the display name set on the RGS object.
Then you can find the object in
CN=Application Contacts,CN=RTC Service,CN=Microsoft,CN=System,DC=contoso,DC=com
You can now hide the RGS workflow from the Skype4B addressbook by setting the msExchangeHideFromAddressBook value to TRUE.
Then updating the addressbook using the following two cmdlets
Update-CsUserDatabase
Wait for the Event log on the CMS master to show that the database is upto date (or wait ten minutes) then;
Update-CsAddressBook
This guide is based on information from Frederik Lefevre‘s post on hiding address book entries, I just made finding the object easier.
http://www.ucprofessional.com/2011/12/hide-contacts-in-lync-addressbook.html