For a drupal 6 site I needed a node edit overlay. This is what I did.

Define the urls ajax/node/%node/edit and nojs/node/%node/edit. The idea is to use path similar to the normal drupal paths just prepended with what ctools modal needs. It needs are minor in that the url path must contain a string nojs and in this case a class attribute ctools-use-modal.

<?php
function annotate_ym_menu() {
$items['nojs/node/%node/%'] = array(
'page callback' => 'annotate_ym_ajax_node',
'page arguments' => array(0, 2, 3),