I am looking forward for way in which excel row will add a new entry everytime QR code is scanned

I am building an app which will use Excel Online in the backend.

The requirement is to have a QR code assigned to a column in excel and everytime someone scans the QR code the data available in the app (i.e. email address) should be added in the column for which QR code is scanned.

This is more of event registration app. the flow will be like

1. The app for each attendee will contain their email id.  

2. Event will have mutiple session and for every session we will have a separate column in the excel workbook. (this is for attendance database)

3. When an attendee scans the QR code for any session, the attendee's email address need to be automatically updated in the backend excel workbook column for the respective session.

If it is not possible per column basis than the next is if possible for single workbook so that I can create a workbook for each session (event) and when someone scans the QR code for that session the enty to be updated in the workbook.

I hope the description is clear, please do share your thoughts about the approach and if you have any idea on how to achieve that please do share.

Regards,

Abhi