Hi Russel! Thanks for your interest in my code!
Unfortunately, it is impossible to link Geolizer with the Cities database
Webalizer (and thus, Geolizer) uses fixed-length tables for country codes (in fact, country codes/names are defined in a webalizer_lang.h file). Database with a plenity of city data would require some kind of dynamic structure, which would require a major rewrite of the Webalizer code