Attribute VB_Name = "Module1"
Public Sub LaskeHinnat()
  Dim Rivi As Long
  Dim Muutos As Double
  Rivi = 5
  Muutos = 1 + Sheets("Hinnasto").Range("C1").Value
  Do While Sheets("Hinnasto").Range("A" & Rivi).Value <> ""
    Range("C" & Rivi).Value = Range("C" & Rivi).Value * Muutos
    Rivi = Rivi + 1
  Loop
  Application.OnUndo "Peruuta hinnanmuutos", "LaskeHinnat_Undo"
End Sub

Public Sub LaskeHinnat_Undo()
  Dim Rivi As Long
  Dim Muutos As Double
  Rivi = 5
  Muutos = 1 / (1 + Sheets("Hinnasto").Range("C1").Value)
  Do While Sheets("Hinnasto").Range("A" & Rivi).Value <> ""
    Range("C" & Rivi).Value = Range("C" & Rivi).Value * Muutos
    Rivi = Rivi + 1
  Loop
  Application.OnRepeat "Hinnanmuutos", "LaskeHinnat"
End Sub