How to update form submission table?

I have a customer who has an elaborate Form. In addition to the questions asked, they need to add some information that is calculated later on. I’ve been able to add such fields using code, and they get updated ok when viewing the table from the editor.

However, It seems I can’t display these fields which were added by code in the dashboard submission table:

I cannot select Score and Grade there, so the website owner can’t see them.

I figured that maybe it will only display elements that are actually in the form. So I added such elements to the form and collapsed them, and then tried to update them in the code. That doesn’t seem to be working though. While the original Score/Grade which I added in code or in the database only (1) get updated, the ones which are in the form (2) stay empty, even when viewed.

Any suggestion on how can add info to the submission table so that the website manager can use it?