Auto populate number sequence

Hi everyone, hoping for a bit of advice
Is there a way to auto populate a number each time a spreadsheet is opened or saved?
to explain, what i would like is if a new job card (excel spreadsheet) is started, it automatically creates the next number in the sequence, ie 001,002,003 etc etc.
That way it automatically keeps track of the latest number.

Thanks in advance

Thanks Marvin, i think that will be perfect