Private Sub MarkerBetween(Delimiter As String, MarkerColor As Color)
 
        With rtbHigh
            Dim pos1 As Integer = -Delimiter.Length - 1
            Dim pos2 As Integer = -1
            Do
                pos1 = FindString(Delimiter, pos1)
                If pos1 >= 0 Then
                    pos2 = FindString(Delimiter, pos1 + 2)
                    If pos2 > pos1 + 2 Then
                        .SelectionStart = pos1
                        .SelectionLength = pos2 - pos1 + 1
 
                        .SelectionBackColor = MarkerColor
                        .SelectionLength = 0
 
                        pos1 = pos2
                    End If
                End If
            Loop While pos2 >= 0 And pos2 = pos1 and pos2 < .Text.Length - 2
        End With
    End Sub
 
 
    Private Function FindString(ByVal txt As String, ByVal start As Integer) As _
      Integer
 
        Return rtbHigh.Find(txt, start + txt.Length + 1,
                            rtbHigh.Text.Length, RichTextBoxFinds.None)
    End Function