My maternal grandfather's name was Odysseas, but when he came to the United States, he changed his name to Frank. On my father's side he had an uncle named Frank. I am not sure that there is a direct correlation between the name Frank and any particular Greek name. I always assumed that my grandfather chose the name Frank so that he could fit in with other nationalities in his business, but to be honest with you, I really don't know.
Good luck with your Greek family history research.
Georgia Keilman nee Stryker (Stratigakos)http://HellenicGenealogyGeek.com