If you’d like to setup your domain to accept anything.domain.com, you can do so with the following guide (Admin access required)
1) Setup the dns with a wildcard A record. Go to Dns Control, and add an "A" record:
* -> 1.2.3.4
where 1.2.3.4 is the IP of your domain.
This will allow anything.domain.com to resolve to your server. Apache does not yet know how to direct that name though.
2) To setup apache, go to:
Admin Level -> Custom Httpd configurations -> domain.com
In the top text area, add this *one* line:

ServerAlias *.|DOMAIN|

then click "Save".
That should be it. Wait a few minutes for everything (apache, named) to be restarted then test it out.
The wildcard subdomains will point to your main public_html directory for the domain.
If you want to change this, it’s probably best not to do step 2, and to setup your own custom virtualhost manually into the /etc/httpd/conf/httpd.conf (DA wont delete/overwrite it there) with the same ServerAlias directive as in step 2.
Other similar uses might be subdomain aliasing, where test.domain.com is the same as test.domain2.com.
You can accomplish this by following step 1) above, then insert the following instead of step 2) above:

|*if SUB|
    ServerAlias |SUB|.domain2.com
|*endif|

which will make any existing subdomain from domain2.com point to domain.com.

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