Tu je výsledok, jedná sa o stĺpce O a P:

Private Sub Worksheet_Change(ByVal Target As Range)
    On Error GoTo ErrorHandler
    Application.EnableEvents = False
    
    If Target.Row = "O" Then
        Target.Offset(0, 1) = Target.Offset(-1, 0) - Target.Value
    End If
    If Target.Row = "P" Then
        Target.Offset(0, -1) = Target.Offset(-1, -1) - Target.Value
    End If
    
ErrorHandler:
    Application.EnableEvents = True
End Sub