Looping through two separate columns of data

I have data in an excel spreadsheet and need to enter it into a backend web admin. The first column is the title of a book, and the second column is metadata for that book (in this case DOIs). I know how to use the for each loop in Keyboard Maestro, but that only works with one set of data. How can I use this for two sets of data that are equal in length? Any suggestions to guides would be great, I will definitely read up, but I've had difficulty solving this problem and I have been using Keyboard Maestro for several years. Thank you!

MacOSX v. 12.4 KM v10.1.1

Start by checking the web backend. Does it have any method of bulk import, or an API you can use to add individual records? Even checking how the form is submitted may get you a more robust solution than trying to replicate what you'd do by hand, in a browser, with KM.

What you find there will determine how you want to massage your data, and that will determine the best way to get it out of Excel.

And if you know how to loop through one set of data -- you know how to loop through two! You just put the second set's operations in the loop with the first. Pseudocode for doing it like you would by hand:

for i from 1 to (count of rows)
    go to Excel
    copy cell (column A, row i) to variable colA
    copy cell (column B, row i) to variable colB
    go to browser
    paste variable colA to form field A
    paste variable colB to form field B
    press Submit
    set i to i + 1

Thanks so much @Nige_S, I appreciate your help! I'm not going to lie, this took me a minute to get working but once I understood using the i variable, I was able to create arrays and loop through them simultaneously in KM. Thanks again for the quick response, I appreciate it!