Say we enter values in A1.
Say the first value is 10 and the next value is 7
Say we want A2 to display -3 (since we reduced A1 by 3)
Enter the following event macro in the worksheet code area:
Dim oldvalue As Variant
Private Sub Worksheet_Change(ByVal Target As Range)
Set t = Target
Set a1 = Range("A1")
If Intersect(t, a1) Is Nothing Then Exit Sub
Application.EnableEvents = False
With a1
Range("A2").Value = .Value - oldvalue
oldvalue = .Value
End With
Application.EnableEvents = True
End Sub
Because it is worksheet code, it is very easy to install and use:
1. right-click the tab name near the bottom of the window
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
