Modify this code to select different column

Hi!
There is a long alphabetized list of clients on the worksheet, and column E contains their last name. At the top of the sheet, there is one button for each letter. Using the code below, you click on the letter you want, and the page jumps to the first row that contains that letter. It works awesome, but I'm looking for it to select the same row, but column D, instead of column E.

How do I modify the code below to select column D instead of E?

 Dim Btn As Object
    Dim cell As Range
    Dim Ltr As String
    Dim rng As Range
    Set Btn = ActiveSheet.Shapes(Application.Caller)
    Ltr = Btn.TextFrame.Characters.Text
    Set rng = ActiveSheet.Range("E10", Cells(Rows.Count, "E").End(xlUp))
    For Each cell In rng
    If StrComp(Left(cell, 1), Ltr, vbTextCompare) = 0 Then
    cell.Activate
    Exit For
    End If
    Next cell
    End Sub

Thanks!