SWG; Wildcards in URLs within categories?

We are evaluating Secure Web Gateway. I would like to create a custom category within SWG that includes all URLs for a specific domain, e.g. http://.somesite.com. I have thus far only figured out how to prefix match, which includes all content beneath a specific site, e.g. http://www.somesite.com/. Is this possible without specifying every website within a domain?

Thanks much.