<code>Private Sub MarkKeyWord(RTF As RichTextBox, ByVal Key As String, _
  ByVal Color As Long, ByVal Bold As Boolean)
 
  Dim sPos As Long
  Dim OldPos As Long
 
  With RTF
    OldPos = .SelStart
 
     <font color=green>' Darstellung kurzfristig abschalten</font>
    .HideSelection = True
    .Visible = False
 
    <font color=green>' Nach Schlüsselwort suchen</font>
    Do
      sPos = InStr(sPos + 1, .Text, Key)
      If sPos > 0 Then
        <font color=green>' Schlüsselwort gefunden</font>
        .SelStart = sPos - 1
        .SelLength = Len(Key)
        .SelColor = Color
        .SelBold = Bold
      End If
    Loop Until sPos = 0
 
     <font color=green>' Darstellung wieder anschalten</font>
    .HideSelection = False
    .Visible = True
    .SelStart = OldPos
    .SelLength = 0
  End With
End Sub</code>