Extendiendo la clase String - Alphanumeric

Código:
'' Alphanumericals are a combination of alphabetical and numerical characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection.



Static Public Function Alphanumeric(strInput As String) As String



  Dim int As Integer

  Dim strSymbol As String



  Dim stxLeters As New String[]

  Dim intKey As Integer

  Dim stxOut As New String[]

  Dim strOut As String



  Dim stxRepin As New String[]

  Dim stxRepout As New String[]

  Dim intRep As Integer



  stxOut.Clear

  stxLeters.Clear



  stxLeters = Split(":a:b:c:d:e:f:g:h:i:j:k:l:m:n:o:p:q:r:s:t:u:v:w:x:y:z: :A:B:C:D:E:F:G:H:I:J:K:L:M:N:O:P:Q:R:S:T:U:V:W:X:Y:Z:á:à:â:ã:é:è:ê:í:ï:ó:ô:õ:ö:ú:ç:ñ:Á:À:Â:Ã:É:È:Ê:Í:Ï:Ó:Ô:Õ:Ö:Ú:Ç:Ñ:0:1:2:3:4:5:6:7:8:9", ":")

  stxRepin = Split("Á:À:Â:Ã:É:È:Ê:Í:Ï:Ó:Ô:Õ:Ö:Ú:Ñ:á:à:â:ã:é:è:ê:í:ï:ó:ô:õ:ö:ú:ñ", ":")

  stxRepout = Split("A:A:A:A:E:E:E:I:I:O:O:O:O:U:N:a:a:a:a:e:e:e:i:i:o:o:o:o:u:n", ":")



  For int = 1 To String.Len(strInput)

    strSymbol = String.Mid(strInput, int, 1)

    intKey = stxLeters.Find(strSymbol)

    If intKey > -1 Then



      intRep = stxRepin.Find(strSymbol)

      If intRep > -1 Then

        strSymbol = stxRepout[intRep]

      Endif



      stxOut.Add(strSymbol)

    End If

  Next



  strOut = stxOut.Join("")



  Return strOut



End