O código que você tem pode ser modificado para usar o método no link do comentário link
Sub DeleteTextAddSignature()
'Import Word functions and search & remove
Dim Ins As Outlook.Inspector
Dim Document As Word.Document
Dim Word As Word.Application
Dim Selection As Word.Selection
Set Ins = Application.ActiveInspector
Set Document = Ins.WordEditor
Set Word = Document.Application
Set Selection = Word.Selection
Dim search As String
search = "search term 1"
Dim search2 As String
search2 = "search term 2"
Dim para As Paragraph
For Each para In Document.Paragraphs
Dim txt As String
txt = para.Range.Text
If InStr(txt, search) Or InStr(txt, search2) Then
para.Range.Delete
End If
Next
'Set to HTML
Dim objItem As Object
Dim objMail As mailitem
On Error Resume Next
Set objItem = Application.ActiveInspector.currentItem
If Not objItem Is Nothing Then
If objItem.Class = olMail Then
ActiveInspector.CommandBars.ExecuteMso ("MessageFormatHtml")
End If
End If
'Get and insert default HTML signature
Dim Signature
Signature = Environ("appdata") & "\Microsoft\Signatures\"
If Dir(Signature, vbDirectory) <> vbNullString Then
Signature = Signature & Dir$(Signature & "*.htm")
Signature = GetBoiler(Signature)
Else:
Signature = ""
End If
With objItem
.HTMLBody = .HTMLBody & Signature
End With
objItem.Display
Set objItem = Nothing
End Sub
' http://www.rondebruin.nl/win/s1/outlook/signature.htm
Private Function GetBoiler(ByVal sFile As Variant) As Variant
Dim FSO
Dim ts
Set FSO = CreateObject("Scripting.FileSystemObject")
Set ts = FSO.GetFile(sFile).OpenAsTextStream(1, -2)
GetBoiler = ts.readall
ts.Close
End Function