Excel Upload - More than 50 columns

It would be super great if when you are uploading an excel file and it had more than 50 columns, if there was an option where you pick one column that is the same in each upload (ideally it is a unique column) and it would use that to fill out the rest of the columns in that item.

Ex: Excel file - 65 columns
Upload first 50
Upload last 15 + 1 column that is unique per line from the first 50
Upload and match to unique column
All 65 columns would then be updated

This would make things a lot easier for those larger files without having to find a workaround or spend hours getting everything uploaded correctly for use.