Thanks Gordon. I actually needed it to exclude all subdomains, but using regex like that looks like very good starting point.
In my case I solved it (just then) even more easily, I changed the include pattern from:
economicdevelopment.vic.gov.au
to
http://economicdevelopment.vic.gov.au
Usually I would leave out the protocol but in this case it seems to have the effect that the crawler ignores all the subdomains, which is what I was after. Nice to have the regex option up my sleeve though.
Cheers