Directory Structure in openGL

What exactly do you mean? You can check out (windows specific) http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/listing_the_files_in_a_directory.asp
on how to get a directory listing. After that if you want to show that information using OpenGL you just need to print it to the screen (see Nehe's tutorial). For expansion and collapsing, you would need to use picking for when the user clicks the mouse on a folder name, then reprint the information with the next level for that folder (or without it, depending on whether is was already expanded)

I want the directory structure layout...with my own names in it...which can be expanded and collapsed etc....