auto generate a comment box based on a cell value that has variable reference cells

I have been given the following code and it works great. I now need to adapt it to the following scenario:

In the attached sheet, the user has to select either, "Suburban" or "Squad" in row 5.
If the user selects, "Suburban" I need this script to compare the values they enter in a given row to the value in column "B".
If the user selects, "Squad" I need this script to compare the values they enter in a given row to the value in column "C".

Look at row 48, for example. If the user enters, "Suburban" in cell D5 then the value they enter in cell D48 should equal "1". If it does not equal "1" then it should proceed with the adding of a comment. Conversely, if the user enters, "Squad" in cell D5 then the value the enter in cell D48 should equal "2". If it does not equal "2" then it should proceed with the adding of a comment.

WHEW! Clear as mud?

Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range) 
     'I want to   exclude columns A and B as well as rows 1, 2, and 3.
    If Target.Column < 3 Or Target.Row < 4 Then Exit Sub 
    Dim MyCmmnt As String 
    If Sh.Name = "DATA" Then Exit Sub 
    On  Error Goto errorout 'Resume Next
    If Target.Value <> Cells(Target.Row, "B").Value Then 
        MyCmmnt = Application.InputBox("Briefly explain the discrepency", "Comment", Type:=2) 
        If MyCmmnt = "False" Or Len(Trim$(MyCmmnt)) = 0 Then Exit Sub 
        With Target 
            .AddComment 
            .Comment.Text Text:=Application.UserName & ":" & Chr(10) & MyCmmnt 
            .Comment.Visible = False 
        End With 
    End If 
errorout: 
    Err.Clear 
End Sub