I will go tomorrow to this location (Saroulla building, where my father's office used to be located and that is facing my school) to take a better view and search for a good spot in the building where I could do the projection. Meanwhile here's a photo that I found on the net, shot by "Bluescape" and posted on "Panoramio". Originally this building embeds two cinemas, one still functioning and turned into a theater "Al Madina Theater" and the other cinema has stopped functioning in the early 90s (according to my father), and is being used as a storage space.
According to Al Madina Theater website http://www.almadinatheatre.com/, the Saroulla cinema was built in the late sixties and was abandoned during the entire period of the Lebanese civil war.
The projection I am planning on Monday does not take place inside the cinema, rather outside it, on the walls of the actual building.