Loop through specific column in each row and add new columns to an existing CSV file

I am trying to loop through each row to read and store the first column only (RefNo). Then, I need to copy the RefNo one by one and paste it on a website to extract some information. Once information is retrieved, I need to add 2 more columns to the CSV file and paste the information there.

The number of rows are always changing everyday depending on the amount of request we get.

I’ve been searching all day on methods to do this but still have no idea how.

See here: How to change values in an existing CSV file