In order to share a file using UNC names you have to join together the file’s name and the file’s location or path. In Windows XP this meant clicking on the file as if to rename it and copy the name then click in the Address bar and paste the name at the end of the path. It is a small inconvenience but, an inconvenience none the less. At first glance it appears this shortcoming was carried over in Windows 7.
Hold down the Shift key and then right-click on the file. A new option in the context menu is available named “Copy as path”. This will copy the path and file name adding quotes around the address. You can then paste the address anywhere you need it.