ClickOnce Update to disk path

I am using ClickOnce deployment for a Visual Studio 2005 windows application. This application is distributed to a file sharing server on a network of which all the computers have access to the server as a mapped network drive x:

say I publish to X:\software\publish\

i also want the software to check for updates from this same path however, when I enter this path into the location during the ClickOnce wizard it says:

Invalid value for 'Update URL' . The string must be a fully qualified URL or UNC path, for example 'http://www.microsoft.com/myapplication" or "\\server\myapplication"

I have tried "\\x\software\publish", "http:\\localhost\x\software\publish", "\\localhost\x\software\publish" these all allow me to publish the sofware but the software then crashes when you run it saying the update location can not be found.

How do I set the update path to a simple disk path for updates? This location will always be static and available.