Simple,You can see the below template and use it accordingly. Its very common to create a virtual host and very simple. Surely below template will work.
<VirtualHost *:8081>DocumentRoot "C:/xampp/htdocs/testsite"ServerName testsite.locServerAlias www.testsite.loc<Directory "c:/xampp/htdocs/testsite">Order allow,denyAllow from all</Directory></VirtualHost>
Also for more reference about virtual host please visit this site. http://www.thegeekstuff.com/2011/07/apache-virtual-host
Thanks,