Thats not a dumb question <img src="{SMILIES_PATH}/icon_wink.gif" alt=";)" title="Wink" />
I'm not sure if we can mask objects with other objects in Construct, I know you can't in MMF2. So if you can in construct, i'll be very happy.
I'm afraid I can't help, I look forward to someone who knows to answer this <img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /> I'd be interested in the solution.