As one last thing, if you're not sure what the UNC path is for your J drive, open up My Computer. You'll see something like
"foldername on 'ServerName' (J: )"
or
"foldername on 'ServerName\foldername\foldername\etc' (J: )"

Basically just put \\ then whatever you see between the ' and ' after "on", then \ again, then the foldername. So my first example would have a UNC path of
\\ServerName\foldername\

and the second would have a UNC path of
\\ServerName\foldername\foldername\etc\foldername\