Just tried it .... yes you can. Make sure you construct the area where you want no resist and paste as "pads" ..... anything else use copper shape (filled) .... if the shape needs to be connected to the "pad" (and is touching it) in the properties box simply give it the pad number.
The alternative method is to define custom resist and paste layers. You can edit an existing technology file and save it under a different name as 'your' copy. Use pad exceptions to change the pad size on the resist and paste layers, then add filled shapes on the layers to define any off-centre areas.
If you're adding shapes to the copper, then use the shape properties to link it to a pad by number. That way it will link to the same net as the pad.