Limit Worksheet_SelectionChange Event To Specific Column

I have some code which enables new comments to be added when a user double clicks a cell, but I want to restrict this to a specific range B5:B125. How do I change the code to reflect this, and add the current Date to new comments added. Here is the first section of the code which sets the range etc...

Option Explicit
Public oldRange As Range
Private Sub Worksheet_SelectionChange(ByVal Target As Excel.Range)
On Error Resume Next
Dim rng As Range
Set rng = Target(1, 1)
oldRange.Comment.Visible = False
With rng
If Not .Comment Is Nothing Then
If .Comment.Visible = False Then
.Comment.Visible = True
Else
.Comment.Visible = False
End If
End If
End With
Set oldRange = Target(1, 1)
End Sub....