To check your computer name do this step...
From the windows start button>>Run>>Type "msinfo32.exe"
This will show the details of System Information,From the "System Summary" check the detail of "System Name" (xxxxxxx) which is your computer name.
So your UNC path would be like:
This entry should be given for two sections after clicking "Add" button ie: for "Selected path" & "File name".
Now the files from that shared location would be added to restore the DB.Dont worry about n/w paths not displaying...Your files are accessible check it...Have a good day.