Dim lPos As Long
  Dim nCount As Long
  Dim sPos As Long
 
  lPos = -1
  sPos = 0
  With RichTextBox1
    nCount = 0
    Do
      lPos = .Find(vbCrLf, lPos + 1)
      If lPos >= 0 Then
        .SelStart = sPos
        .SelLength = lPos - sPos + 1
 
        nCount = nCount + 1
        Select Case nCount
          Case 1
            .SelFontName = "Arial"
          Case 2
            .SelFontName = "Times New Roman"
          Case 3
            .SelFontName = "MS Sans Serif"
        End Select
        sPos = lPos + 2
 
      End If
    Loop Until lPos < 0
  End With