Tracking Stored variable and cloud variable database rows

I am completing an app that enables the user to evaluate a situation in a number (8) of factors using a Slider for each evaluation. All this is good and I can store in device and in Airtable (this avoids filtering the Airtable database, and provides individual security.
My difficulty is that the evaluation has a start date and an end date for each evaluation. I am recording the start date and the evaluation scores ok. My difficulty is ascertaining the same row to insert the end date for that same evalaution (which may be a week later).
The end date detemination has a separate block set.
If I insert a specific row number in the block it all works well.
Now I need to track the relevant row number so the user can complete the correct row.
Do I need to use a row counter? If so how. Any solution welcome.
Any help appreciated.