Sorry but we cannot set this up as we don't allow customisation to the httpd.conf file.
So I went about looking to see if I could work around it by using a .htaccess file.
I came across this post, which looks promising.
If anyone can throw some light on it, I think this would help a lot of people when the host will not allow wildcard DNS.
http://www.sitepoint.com/forums/showthread.php?t=141416
