I run a domain that will require numerous subdomains, ie videos.mydomain.com, images.mydomain.com, forums.mydomains.com, etc.

Currently when adding a subdomain (or subserver using Virtualmin's terminology) the new domain is added to /home/user/domains/subdomain.mydomain.com/

I would like to simplify this so that any new domains I add are added to:
/home/user/domains/subdomain/

But I cannot figure out how to do this. Is it possible to make it so that when I add a domain to mydomain.com I would only have to type in the highest level prefix (ie. "subdomain" instead of "subdomain.mydomain.com") and then have the BIND and APACHE scripts automatically prepend ".mydomain.com" to their directives? This would cause the directory to be created as /home/user/domains/subdomain/ like I would like.