Write out Maxwell's Equations component wise in cylindrical coordinates in their most general form. Remember that each field component can be a function of all three spatial dimensions as well as time. You should end up with eight equations: the two divergence equations, and three equations for the curl equations when they are separated component wise. At this point, assume that all source terms are present-that there exists both a charge density and a current density throughout the region of interest. This is the form you would need if you had to solve a fully general program for a wave form on a coaxial cable.