 <p>You could do something like this:</p> <pre><code>Dim sLowerCase As String = "qwertyuiopasdfghjklzxcvbnm" Dim sUpperCase As String = "MNBVCXZLKJHGFDSAPOIUYTREWQ" Dim sNumbers As String = "1234567890" Dim x = New Random(Now.GetHashCode) Dim y = {sLowerCase, sUpperCase, sNumbers} Dim z = y(x.Next(0, y.Length)) Debug.Print(z) </code></pre>