Discovering a UNC

Question

I am currently working on a Windows Service, that needs to update files through a Lan environment. The problem lies in that while trying to retrieve and open the file through a mapped network drive, It won't let me. The only way that I can get access to it is through My Network Places if I reference the computer by its UNC. How do you discover the a UNC with a Mapped Path. I have found no way in .Net so far. Any help would be greatly appreciated. Max