text: Add an Alias (CNAME) Resource Record to a Zone
  Applies To: Windows Server 2008, Windows Server 2008 R2 server-1, for the server computer that hosts these services.
  Membership in the Administrators group, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at.
  Adding an alias (CNAME) resource record to a zone
  Open DNS Manager.
  In the console tree, right-click the applicable forward lookup zone, and then click New Alias.
  In Alias name, type the alias name.
  In Fully qualified domain name (FQDN) for target host, type the FQDN of the DNS host computer for which this alias is to be used.
  As an option, you can click Browse to search the DNS namespace for hosts in this domain that have host (A) resource records already defined.
  Click OK to add the new record to the zone..