Jabbara,
I don't agree with that. Lift is the sum of all vertical forces on the aircraft, and in cruise is equal to weight. Yes, the wing has to produce extra lift to over come the downforce of the tail (in most aircraft- some models actually have a lifting tail), but total lift is the sum of these.
Co-efficient of lift refers to the whole airframe, not just the wing, so entering values to the equations L=C 1/2 RHO V^2, with the assumption that in cruise L=W is valid as far as I can see.