Use the Word document inspector to edit the message directly e.g. as follows. The only major snag with this is that not all senders have their sender names formatted as you might expect. Some, for example, have the surname first.
Code:
Sub AutoAddGreetingtoReplyAll()
Dim oMail As MailItem
Dim oReply As MailItem
Dim GreetTime As String
Dim olInsp As Inspector
Dim wdDoc As Object
Dim oRng As Object
Select Case Application.ActiveWindow.Class
Case olInspector
Set oMail = ActiveInspector.currentItem
Case olExplorer
Set oMail = ActiveExplorer.Selection.Item(1)
End Select
Set oReply = oMail.Reply
With oReply
Set olInsp = .GetInspector
Set wdDoc = olInsp.WordEditor
Set oRng = wdDoc.Range
.Display
With oRng
.collapse 1
.Text = "Hi " & Split(oMail.SenderName)(0) & "," & vbCr
.Font.Name = "Century Gothic"
.Font.Size = 11
.collapse 0
.Select
End With
End With
lbl_Exit:
Set oMail = Nothing
Set oReply = Nothing
Set olInsp = Nothing
Set wdDoc = Nothing
Set oRng = Nothing
Exit Sub
End Sub