Access mounted volumes on Windows from LC?

[Ben Rubinstein]

I need to deploy an app to a remote Windows machine which is not under my control.

The app needs to inspect a folder on a mounted drive.  Traditionally this was 
just mounted as a letter, e.g. "Z:\" or similar; my app worked fine.

But modern Windows systems use volume names, so a folder on such a drive may 
have the path (in Windows notation) like:
	\\volname\folder1\folder2

Attempting to access it using any of the forms
	/volname/folder1/folder2
	\volname\folder1\folder2
	\\volname\folder1\folder2
	//volname/folder1/folder2

fails (although the error is different in the last case).

How can I access such a path?

TIA,

Ben