Public Function patron(referencia)
 Dim objRegex As VBScript_RegExp_55.RegExp
 Dim colMatch As VBScript_RegExp_55.MatchCollection
 Dim vbsMatch As VBScript_RegExp_55.Match
 Dim colSubMatch As VBScript_RegExp_55.SubMatches
 Dim sMatchString As String
 Dim i, num, numT As Integer
 Set objRegex = New VBScript_RegExp_55.RegExp
 objRegex.IgnoreCase = True
 objRegex.Global = True
 objRegex.Pattern = "[^A-Za-z ]+"
 Set colMatch = objRegex.Execute(referencia)
 numT = colMatch.Count
 objRegex.Pattern = "[A-Za-z ]+"
 Set colMatch = objRegex.Execute(referencia)
 num = colMatch.Count
 On Error GoTo ControlErrores
 If numT = 0 And num >= 0 Then
   patron = 1
 Else
   patron = 2
 End If
 Exit Function
   ControlErrores:
   MsgBox ("en patron " & Err.Number)
 Select Case Err.Number
   Case 13
   Case 9
   Exit Function
 End Select
End Function