title: How to use a relative path of a File in C#
body: <p>I am making a launcher that will open other programs.
  The programs will be in the same folder or in a sub-folders of the launcher.
  Their full paths are unknown to me because user chooses where to save them.
  It may be disc C, D, E, D/folder/newfoler54/sdfsdfsdf/program.exe, etc.
  Show how to use relative paths for this purpose</p>