Just successfully tested this.
Add a “Code by Zapier” step and choose Run Javascript.
Setup the inputs as I have below.
The “search” part will reference the email you want to find the rowID for.
Now here’s the code:
let emails = inputData.emails.split(",");
let rowIDs = inputData.rowIDs.split(",");
let index = emails.findIndex(email => email.includes(inputData.search));
output = {rowID: rowIDs[index]};
I split the emails and rowIDs into arrays, then find the index of the email that matches the search term, and return an index.
I finally return the output as the rowID that match the index I found above.