Lync photos in Active Directory - how to retrieve, how to find

To retrieve user photos from Lync, for example to put download photos and put in thumbnailPhoto in Active Directory.
Database: RTC

select UserAtHost,convert(varchar(4000),convert(varbinary(4000),Data))
from PublishedStaticInstance,Resource
where ResourceId = PublisherId
and convert(varchar(4000),convert(varbinary(4000),Data))
like '%%'

Steps (once a day):

• export data from RTC database
• loop for all photos
• download photo
• if needed - scale down to 96x96
• put in thumbnailPhoto

Laast photo update - can be stored in extensionAttributeX (one of available numbers). Why to store photos in both locations? Not every workstation has got Lync 2013 client or newer, the same is for still not migrated all users from Exchange 2010 so... it's better to have all the data in both places.