Visual Basic para Aplicaciones - Generar numeros sin repeticion

Dim buf As String

Private Sub fai(a, i, l)

Dim q$, t%, z$, p$

If (i < l) Then

   q = a

   For t = i To l - 1

       z = VBA.Mid$(q, i + 1, 1)

       If (t = i Or Mid$(a, t + 1, 1) <> z) Then

          p = Mid$(q, t + 1, 1)

          Mid$(q, t + 1, 1) = z

          Mid$(q, i + 1, 1) = p

          Call fai(q, i + 1, l)

       End If

   Next

Else

     buf = buf + a + vbCrLf

End If

End Sub

Private Sub test()

Dim s$

s = "1234"

buf = ""

Call fai(s, 0, VBA.Len(s))

MsgBox buf

End Sub