PML for 2D FDFD (aperiodic)

I am using a FDFD code (written by Dr. Raymond) to solve periodic structures where there is a PML layer on the y-boundaries while x-boundaries are periodic with NO PML. I need to modify this code to fit for aperiodic structures, i.e. to surround the whole domain with PML. Can anyone help me with that ?
hxxp://read.pudn.com/downloads197/sourcecode/math/927043/fdfd2d.m__.htm
(replace xx with tt)

Any help please ?