Open the Lync Server Management Shell (Start –> All Programs –> Microsoft Lync Server 2010 –> Lync Server Management Shell)
2. Enter the following PowerShell command
[sourcecode language="powershell"] Set-CsUser -Identity “sip:sherift@coex.com” -PrivateLine “Tel+20125242000” [/sourcecode]
You forgot the colon after Tel.