View Column Numbers in Excel instead of R1:C1 Letters
Ever wanted Excel to display column numbers instead of letters (think CSV imports!):
Microsoft Excel can be configured to display column labels as numbers instead of letters. This feature is called “R1C1 Reference Style”, and though it can be useful, it can also be confusing if inadvertently enabled.
You can select between the two modes quite easily. Read more at https://kb.wisc.edu/page.php?id=781.