Attribute VB_Name = "AmountToWords"
' Convierte un número a palabras en español. Uso: =SpellNumber(1234)
Function SpellNumber(ByVal n As Double) As String
    Dim grupos As Variant, parts As String, idx As Long, num As Long, chunk As Long
    grupos = Array("", " Mil", " Millones", " Mil Millones")
    num = Int(n)
    If num = 0 Then SpellNumber = "Cero": Exit Function

    idx = 0
    Do While num > 0
        chunk = num Mod 1000
        If chunk > 0 Then parts = TresDigitos(chunk) & grupos(idx) & " " & parts
        num = num \ 1000
        idx = idx + 1
    Loop
    SpellNumber = Trim(parts)
End Function

Private Function TresDigitos(ByVal n As Long) As String
    Dim u As Variant, dec As Variant, cien As Variant, s As String
    u = Array("", "Uno", "Dos", "Tres", "Cuatro", "Cinco", "Seis", "Siete", "Ocho", "Nueve")
    dec = Array("", "Diez", "Veinte", "Treinta", "Cuarenta", "Cincuenta", "Sesenta", "Setenta", "Ochenta", "Noventa")
    cien = Array("", "Ciento", "Doscientos", "Trescientos", "Cuatrocientos", "Quinientos", "Seiscientos", "Setecientos", "Ochocientos", "Novecientos")
    If n = 100 Then TresDigitos = "Cien": Exit Function
    If n >= 100 Then
        s = cien(n \ 100) & " "
        n = n Mod 100
    End If
    If n >= 10 Then
        s = s & dec(n \ 10) & " "
        n = n Mod 10
    End If
    If n > 0 Then s = s & u(n) & " "
    TresDigitos = Trim(s)
End Function