Adding elements to wp_list_pages (within , but before )

If I Understood your question right, instead of wp_list_pages, you can use a custom query using get_pages e.g.

$args = array(
'sort_order' => 'ASC',
'sort_column' => 'menu_order',
'hierarchical' => 1,
'exclude' => '',
'child_of' => 0,
'parent' => -1,
'exclude_tree' => '',
'number' => '',
'offset' => 0,
'post_type' => 'page',
'post_status' => 'publish'
);
$pages = get_pages($args); 
foreach($pages as $page){
 echo '<li><div><a href="'.get_page_link( $page->ID ).'">'.$page->post_title.'</a></div></li>';
}

Some of the code in the $args could probably be removed though