Aqui está um exemplo de macro super simples:
Sub MaintainHistory()
Dim s As String, n As Long, v As Variant
v = Rnd()
Range("A1") = v
If Range("B1") = "" Then
Range("B1") = v
Else
n = Cells(Rows.Count, "B").End(xlUp).Row + 1
Range("B" & n) = v
End If
End Sub