I have never seen a questionnaires with question numbered with natural numbers only.
So I added a new (not mandatory) attribute to each question and I can see/use it in "order questions" web page, "edit questions" web page and, obviously, in questionnaire rendering.

Attached are my patches to four files for the questionnaire release for MOODLE 1.9.
TAKE CARE. the patch for questions.inc INCLUDES the patch provided for CONTRIB-268 so , by applying this patch you also get the changes proposed in that contrib issue.

I also added one more field to my table 'questionnaire_question'.
It is: name: numberalias, type: char(15), collation; utf8_unicode_ci, Null: no
I don't know how to change the questionnaire db files in order to update the user database at the module update. If you like this new feature, please provide it.