probably the best workaround I can think of for this is to have the SP admin person set up a private shared space and a connection in that space, and use an app in that space to store the needed files for the needed people into different shared spaces.
In my experience the person who owns the connection needs to be able to view the SP site homepage, the share documents folder and every folder along the way to the folder with the needed files. I have seen this documented anywhere
we are testing the other workaround the other folks have mentioned here... ignoring the initial error, and then manually typing in or pasting in a path to the folder
made up example:
Shared Documents/Folder1/Folder Number two/tired of all these folders/
was able to confirm, that if the user has proper sharepoint access to the one folder where the files are, even if the error occurs (System.UnauthorizedAccessException, Access denied) when using the select wizard, there are two ways to get it to work...manually type in the path to the folder in the folder box and press enter... or manually create the load script and manually do the LIB statement to build the proper path to the file there.
the easiest way to do the second option is to put a copy of the file on a different SP site where your connection fully works (can select and browse), use the wizard to create that load script and then edit the LIB statement to use the other connection, and manually fix the path to the file there in the LIB statement. this is a decent workaround when the SP admins cannot grant more access to the site.
