This little HowTo is for those that have a little knowledge about Ensim running on Linux.
This was tested on Ensim 4.0.4 and Apache 2.0 - It should work for all Ensim 4.0.x releases.

Creat a text file in /etc/httpd/conf/sitexx folder and I call it "wildcards".

Then using your favorite text editor add "ServerAlias *.domainname.com" without the quotes to the wildcards file and save it.

Edit /var/named/db.dominname.com file and change
www                       A       xxx.xxx.xxx.xxx
to
*                       A       xxx.xxx.xxx.xxx

of course where "xxx.xxx.xxx.xxx" would be your real IP for your site.

Restart apache, bind  and webppliance:
/etc/init.d/httpd restart
/etc/init.d/named restart
/etc/init.d/webppliance restart

Test your site url.

NOTE: This is used with .htaccess using rewrite rules to allow URLS to redirect to subdomains. ie: http://www.yourdomain.com/index.php?greatsite to point to http://greatsite.yourdomain.com/ - Many scripts use this as in blogging software like BlogSystem and BlogHoster.

Enjoy!