GetRandomNumber in asp.net

Public Shared Function GetRandomNumber() As String
        Dim rand As New Random()
        Dim newpassword As New StringBuilder("")

        For index As Integer = 1 To 2
            newpassword.Append(CChar(CChar(CStr(rand.[Next](65, 90)))))
        Next

        For index As Integer = 0 To 2
            newpassword.Insert(rand.[Next](0, 3 + index), Convert.ToString(rand.[Next](0, 9)))
        Next

        Return ("OD" + newpassword.ToString() + DateTime.Now.Day.ToString())
    End Function