Resolving domain to www.----.com

This is a minor point but it's bugging me. I've been using self-hosted WP for a long time but new to multisite.

In the "normal" WordPress install under Setting => General Settings you can specify that you want to resolve to http://www.whatever.com and not http://whatever.com. MS doesn't seem to have that functionality. Is it possible to do this or are we going to be using everything without the www?

Thanks