Hi Danivici,
Make two profiles, one of the cross section of the screen (profile 1), and one of the cross section of the curved shape (profile 2 - perpendicular to the screen). Use SEO to subtract one away from the other. Leave the carving shape in place but put it on a hidden layer.
I've used the complex profile tool (in AC10 and above), but you will have to use the profiler goodie as AC9 doesn't have this. There is probably a link on your 'Help' menu to the goodies if you don't have this installed already.
Hope that helps!