Yes, it's possible to do a VBA macro or an external program to validate a sheet. But there is no built-in tool you can use to say to excel "this column must al

Yes, it's possible to do a VBA macro or an external program to validate a sheet. But there is no built-in tool you can use to say to excel "this column must always be a number, don't ever allow it to be autodetected as a date" or "this column must always have a formula, if the formula doesn't exist or is a static number, alert the user". You can lock cells, but who bothers doing that in the real world.