County lookup desktop tool

I need to develop a small desktop tool that will look up: a) the county that a specific city/state is in b) the location of a newspaper head office (taken directly off a online newspaper website). Full specs are attached. The output needs to be in an excel file. Program can be developed in C# or C++ and should be multi-threaded. NOTE: Testing the program functionality from start to finish including error checking is a requirement of this project.