transmission line feeding in FDTD matlab code

hi.
I have a problem in feeding of my monopole antenna.I have a monopole antenna above ground palen.I want to simulate an coaxial line feeding for my antenna.for this purpose I want to use from a virtual 1D-transmission line for coaxial line modeling.but I have a question:
in addition to using from transmission line equations in FDTD code (equations of V,I,...),do I have to physically draw inner and outer of coaxial line at drawing of FDTD space?i,e do I have to set tangential E-fields within inner of coaxial line and on the outer of coaxial line = 0?
or only 1D transmission line virtually added to my FDTD grid?and I don't have to set:E-tangent=0?
on the other hand,do I have to draw ground plane perfectly or I have to set a hole at ground plane for coaxial line?
which of following pictures for my FDTD space (physically) are correct?
1. hole on the ground plane without modeling of coaxial line (physically):

2. hole on the ground plane with modeling of coaxial line (i,e set E-tangent at inner of coax and on the outer of coax =0)