Connect to SharePoint Online excel workbook

[ITWorkingSolutions]

Hey guy's, I have a humble VBA solution for updating the underlying excel workbook that acts as the external data source. Needs more refinement, and maybe convert to add-in. Nothing to compare with Nikolay Belykh's BackSynch add-in, but achieves the basics. This I share that it may help others (see attachment). Sorry I have not commented for sharing, and... it's basic. The problem I face is linking to a workbook located in SharePoint Online. Can't find how to read and write to an excel workbook located in SharePoint Online using ADO or other data connection mechanism. Note not interested in linking to SharePoint list. Thank you for any pointers you can provide.

[Nikolay]

Looks like you have checked out my BackSync tool 
Just wondering, why didn't it work in your case (so that I could improve)?
In principle, it should work with share point list as well.

[ITWorkingSolutions]

No problem with your add-in the issue is I need to update an excel workbook saved in SharePoint Online. That's where I'm stuck. ADO doesn't want to play, and I'm not sure if a) it can't done; b) authentication issue; c) should be using another provider.

[Nikolay]

Thank you for the response! I see.
So you want to synchronize data not with a SharePoint LIST but with an excel FILE stored in a SharePoint document library, right.

[ITWorkingSolutions]

Yep that's the sum of it.