requesting help to construct pattern for author/category

okay, this may be very obvious to some of you, but i'm at a bit of a loss - i followed: http://drupal.org/node/212987 and pasted:

  $title = 'This is a question written by '. $_POST['name'];
  return $title;

...but i want to also show the CATEGORY/TAXONOMY term selected from a required dropdown for the content type such that the displayed autotitle is something like:

A question from (username) about (category)

any advice?