The original motivation of this research is to describe comprehensive solutions based on Finite Difference Method (FDM) together with its software implementation that can handle the infinity long conductor. This paper focuses on developing FDM procedures for solving the interface regions, defined as regions where the step sizes change. Attention has been paid in this problem for creating robust and efficient techniques for solving the complex electromagnetic field at long distance from the transmission line based on a variable step size for the grid of FDM. Reduction in memory requirements has been achieved in these approaches. The industry has identified that there is a pressing need for a comprehensive method together with its software implementation that can handle the infinity long conductor problem. The research results of the project have immediate and practical application to the power industries.