I'm not sure exactly what you're trying to do without seeing what the code you want to add is and where it's to be added. Here is how you would go about registering a new sidebar and adding it in to your child theme. In this example we'll be adding a widget to the above_mainasides hook. This allows you total control over the markup to insert whatever code you need. I've added classes in this example that generally follow thematic's methodology. If you remove them be warned that the layout will likely go wonky for lack of styling but you probably can work that out.
I'm not sure how to instruct you to filter the existing thematic_widget_areas in light of new changes coming to that area of the framework.
function register_my_widget_area() {
if ( !function_exists('register_sidebars') )
return;
// Register Widgetized area
register_sidebar(array(
'name' => 'Bovine Aside',
'id' => 'bovine_aside',
'before_widget' => '<li id="%1$s" class="widgetcontainer %2$s">', // or add your own markup here
'after_widget' => '</li>', // or add your own markup here
'before_title' => thematic_before_title(), // or add your own markup here
'after_title' => thematic_after_title(), // or add your own markup here
));
}
add_action('init','register_my_widget_area');
function add_bovine_aside() {
if ( is_sidebar_active('bovine_aside') ) { // will display only if there are active widgets for this sidebar
echo '<div id="bovine" class="aside main-aside">'. "\n" . '<ul class="xoxo">' . "\n"; // or add your own markup here
dynamic_sidebar('bovine_aside');
echo '</ul>' . "\n" . '</div><!-- #bovine .aside -->'. "\n"; // or add your own markup here
}
}
add_action('thematic_abovemainasides','add_bovine_aside');
hope it helps- good luck- I'm off to the beach so I probably wont check to see how this worked for you for a few days.