Sub Column()
Set rec = Worksheets("Rec")
Dim LastColumn As Integer
    LastColumn = rec.Range("AF1").End(xlToLeft).Column
    MsgBox LastColumn
End Sub

Worksheets("Лист3").Range("B4").FormulaLocal = "=Лист1!A4" 'где Лист1 всегда крайний левый

Sub test()
Back "HILO_STANDARD", "Card 10 or further", "back_price", 1.23
End Sub

Sub test()
Back "HILO_STANDARD", "Card 10 or further", "back_price", "Q25"
End Sub

Sub test()
Dim amount10 As String
  amount10 = ("Q25")
  Range(amount10).Select
  Back "HILO_STANDARD", "Card 10 or further", "back_price", "amount10"
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
   If Target.Address <> "$O$7" Then Exit Sub
   If Target = Back Then Call Back
End Sub