To Configure Two website with different DNS On single IP??

Hello To all Respected Expert,

                               I am using Window server 2008 R2.I Have Configured DNS on my server e.g. 'abc.com' .Its work successfully on my Company Local intranet i.e. In My Company Every employee  can access My website using the DNS abc.com.

                               Now The Problem is this I have to Configure another website on my server on different Port on same ip.I Need different DNS for it .So Please guide me How I can Configure another DNS On MY server which respond to same ip on the different port .Please Help me Its Very urgent..

Thanks