Wants to apply vba code to multiple cell

I want to apply below vba code to cell range F11:F2000 and want to get result relatively

please help

Private Sub Worksheet_Change(ByVal Target As Range)
If Target <> Range("F11") Then Exit Sub

ActiveSheet.Unprotect ("Undo")

If Range("F11").Value = "3" Then
Range("G11").Value = ""
Range("G11").Locked = True
Range("H11").Locked = False
Range("I11").Value = ""
Range("I11").Locked = True
End If

If Range("F11").Value = "5" Then
Range("G11").Locked = False
Range("H11").Value = ""
Range("H11").Locked = True
Range("I11").Locked = False
End If

If Range("F11").Value = "7" Then
Range("G11").Locked = False
Range("H11").Locked = False
Range("I11").Locked = False
End If

If Range("A1").Value = "" Then
Range("B1").Locked = False
Range("C1").Locked = False
Range("D1").Locked = False
End If

ActiveSheet.Protect ("Undo")

End Sub