I don't understand what you want to accomplish. If you want Virtual Hosting, you will need the following
resolves to xxx.xxx.xxx.xxx
also resolves to xxx.xxx.xxx.xxx
yet again resolves to xxx.xxx.xxx
In /etc/httpd/conf/httpd.conf, under section 3 'Virtual Hosts', you will need to define www.site1.com
as /var/www/html/site1, www.site2.com
as /var/www/html/site2, etc. When you access the httpd server via the name www.site2.com,
you will automatically read the index from /var/www/html/site2. Take a look at the examples in the httpd.conf file for more guidance.
If this isn't the type of set up you are looking for at all, you'll need to refine your question a little more.