This post describes how to add a Subject Alternative Name (SAN) to a secure Lightweight Directory Access Protocol (LDAP) certificate. The LDAP certificate is submitted to a certification authority (CA) that is configured on a Microsoft Windows Server 2003-based computer. The SAN lets you connect to a domain controller by using a Domain Name System (DNS) name other than the computer name. This article includes information about how to add SAN attributes to a certification request that is submitted to an enterprise CA, a stand-alone CA, or a third-party CA.
A step-by-step is on following site: http://support.microsoft.com/kb/931351