It's been a while since I've needed to use this method so I'm not sure if it still works, but in the past I've had success by linking to SharePoint via a local Excel connector. There was an option in SharePoint to have a folder on my computer that synced to its related SharePoint folder, so I just pointed the connector to files in that as if it were a standard local folder. The major downside was that it couldn't run automatically unless you knew you'd be online at the scheduled time, so I just had a connector group in DataLink that I ran as needed.