How to capture a cell value in Excel when a cell updated

Question

I have a cell in Excel that gets updated on basis of RAND() function. Each time I update the cell, I want to capture the previous values in a separate column. So that I can compute mean later on.

How to achieve this??

Answer 1

Copy below into Worksheet module and change "A1" cell:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not (Intersect(Target, Range("A1")) Is Nothing) Then
    i = i + 1
    Worksheets("Sheet1").Cells(i, 2).Value = Worksheets("Sheet1").Cells(1, 1).Value
    End If
End Sub