Say we want the sequential number in Sheet1, cell A1. In the workbook code
area, insert the following event macro:
Private Sub Workbook_Open()
With Sheets("Sheet1").Range("A1")
..Value = .Value + 1
End With
End Sub
Because it is workbook code, it is very easy to install and use:
1. right-click the tiny Excel icon just to the left of File on the Menu Bar
2. select View Code - this brings up a VBE window
3. paste the stuff in and close the VBE window
If you save the workbook, the macro will be saved with it.
To remove the macro:
1. bring up the VBE windows as above
2. clear the code out
3. close the VBE window
To learn more about macros in general, see:
http://www.mvps.org/dmcritchie/excel/getstarted.htm
To learn more about Event Macros (worksheet code), see:
http://www.mvps.org/dmcritchie/excel/event.htm
For more information on this topic, see:
http://www.mcgimpsey.com/excel/accumulator.html