built-in grammars in VoiceXML

Hi,

I like pretty much the idea of the built-in grammars.

But in a mixed-initiative dialogue I would like to be able to
ask for a phone-number and process not only input containing only
the number but as well phrases like:
   "my number is 123456789"
   "please dial 123456789"
   and so on

So it would be great to be able to combine the built-in grammars (in
this case
for example the phone-grammar) with any self-designed grammar.

Is this possible by defining for example an "import" statement in my own
grammars?
If it is not, is it planned to provide this behaviour in the future?



Stefan