Create IFR Point?

Hi -Is it possible to create an IFR point (say on the Space Needle in Seattle)? I am using HSI values to guide pilots with an external device (I know the highway in the sky does the same). Additionally, does anyone know specifically how the highway in the sky is calculated? We want to measure deviation from a desired path, and using HSI is not ideal, as it gets more sensitive the closer you get and caps at +1 or -1 for both vertical and horizontal values. Thanks for any help.