Your diagram shows one way to measure where the CG of the model is located; HOWEVER, it does not tell you where the CG should be for stable flight.

I can't tell from your post, but somehow I get the impression that you are designing a plane? I have some simplified formulas for determining the Neutral Point (NP.) CG on a wing/stab plane typically needs to be in front of the NP. The NP is dependent upon many factors such as the MAC (mean aerodynamic chord) of the wing and stab as well as the distance or moment between the MAC of the wing and stab. Unfortunately, the formulas are at home and I'm not home now. If you are building a plane, post accordingly and I'll try to locate the equations when I get home.