Howdy,
CrossOver works exactly like any other Mac application. So if you pick a file
in question and hit Command-I or File...Get Info, you'll see the information about
what application will open a given file. You can set your preferences there at any time.
Also, as indicated on the trial page and the trial email you should have gotten,
we're happy to take pre sales support questions at sales -at- codeweavers dot com.
Cheers,
Jeremy White
CodeWeavers