Sub GenerateRandomString(StrLength As Int) As String
    Dim RndString As String
    Dim RndNumber As Int
    Do While RndString.Length < StrLength
        RndNumber = Rnd(36,96) 'Yep, 123, because the last number is "exclusive"
        If (RndNumber >= 48 And RndNumber <= 57) Or (RndNumber >= 65 And RndNumber <= 90) Or (RndNumber >= 97 And RndNumber <= 112) Then
            RndString = RndString & Chr(RndNumber)
        End If
    Loop
    Return RndString
End Sub

Dim a As String 
a = "h4w840ffm2gf9ewn40"
Log(a.ToUpperCase)


'result: H4W840FFM2GF9EWN40