VAMT Tools Query - find machine

I want  query all machine running windows 7 and server in below OU

Can you please give me the exact LDAP query for the 2 OU below , so I can check status of our license 

1. OU For Workstation   (find ---> windows 7)

abc.local/ALASKA/Computers/Workstation

2. OU For Windows    (find ---> windows 2008 R2)

abc.local/ALASKA/Computers/server

Robert