access some class outside from inside scxml file

[Zuo, Tao]

Hi all,
I 'd like to access some class outside scxml .
But this piece of code below from the specification seems silent. 
Did I miss anything or it is still not supported?
Any suggestion  please?

Example: <script> in executable content to manipulate the data model
<state id="updateDM">
    <onentry>
      <script>
        _data.myDate = new Date(); 
        updateCounter();
      </script>
    </onentry>
</state>

Regards,
ZuoTao