I had also this type of Problem, but the server was Win2000. I did some tricks to handle this.
1- Don't Map the drive, connect using \\servername\foldername (using set path to in application sartup), but the user can still browse the folder using Explorer.
2- Add $ sign at the end of the foldername$ (\\servername\foldername$), this will hide the folder. Only the user who knows the foldername can browse to the folder.

You will have to fix the path in you application code.