Sub Try()

Dim x, a, BonRow, BonCol, Bon As Integer

Bon = ActiveCell.Row = 2 And ActiveCell.Row <= 12
BonRow = 12
BonCol = 4

If Bon And (ActiveCell.Column = 2 And ActiveCell.Column <= 4) Then
Cells(2, 4).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 5 And ActiveCell.Column <= 7) Then
Cells(2, 7).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 8 And ActiveCell.Column <= 10) Then
Cells(2, 10).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 11 And ActiveCell.Column <= 13) Then
Cells(2, 13).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 14 And ActiveCell.Column <= 16) Then
Cells(2, 16).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 17 And ActiveCell.Column <= 19) Then
Cells(2, 19).Select
x = BonRow
Else
If Bon And (ActiveCell.Column = 20 And ActiveCell.Column <= 22) Then
Cells(2, 22).Select
x = BonRow

End If
End If
End If
End If
End If
End If
End If
End If

Do

ActiveCell.FormulaR1C1 = "=(RC[-2])+(RC[-1])"
ActiveCell.Offset(1, 0).Select
ActiveCell.FormulaR1C1 = "=(RC[-2])+(RC[-1])"

Loop Until ActiveCell.Row = x

End Sub