I've been searching high and low for a solution to this but I've only found lots of answers for Google Apps instead of Excel Online. Not sure if the Google Apps script can be used in Excel Online, but here goes anyway.
What I'm looking for is guidance on how to create an 'onEdit' type script for an Excel Online spreadsheet that will insert a timestamp in the row (let's say A10) where a cell in a different column/same row (let's say N10) is changed.
Any help would be HIGHLY appreciated!