Secondary menus from Module possible?

Is it possible to create a secondary links menu from within a module?

I don't see a way to access this from hook_menu

What I'd like to do is to create a secondary menu at runtime.

I've tried putting something like this in the callback of my module display page

global $secondary_links;

$terms = taxonomy_get_tree(5);
	$secondary_links= "<ul class='tabs secondary'>";
	foreach($terms as $term) {
		$secondary_links.="<li><a href='/country/$country/".$term->tid."'>".$term->name."</a></li>";
	}
	$secondary_links.= "</ul>";

But its not working.

I can put code into the hook_menu, but I don't see how to make a secondary menu from there.

Any clues?