To get Lync specific information you must have Lync server group permission. Means Lync specific permission is must to perform Lync server or user specific work.
4 Find the ‘RTCUniversalUserAdmins’ from Active Directory User and Computer right click on it and click on properties > Member > Add > type user name who want to enroll or search Lync user object. And click Apply > OK
Now you login on Lync server and open ‘Lync Management Shell’ and find or enroll user for Lync.