How can I name the template file for the edit page of a certain content type?

Question

I would like to override only the edit page of a certain content type. Theme developer module says:

page-"content_type".tpl.php < page-node-edit.tpl.php < page-node-"nid".tpl.php < page-node.tpl.php < page.tpl.php

If I use page-"content_type".tpl.php, it also overrides the node view page and if I use page-node-edit.tpl.php it overrides the edit page of all content types.

Update:
I tried the code below, and put it in my template.php but it doesn't work.

function my_theme_preprocess_page(&$vars) {
 if (isset($vars['node'])) {
   $edit_or_add=basename($_GET['q']);
    if ($edit_or_add=='edit' || $edit_or_add=='add') {
      $vars['template_files'][]='page-' . str_replace('_','-',$vars['node']->type . '-' . $edit_or_add);
    }
    else {
      $vars['template_files'][]='page-' . str_replace('_','-',$vars['node']->type);
    }
  }
}

Answer 1

function my_theme_name_theme($existing, $type, $theme, $path) {
  return array(
    'story_node_form' => array(
        'arguments' => array('form' => NULL),
        'template' => 'node-story-edit'
    )
  );
}

This code from here worked for me, for example for the story content type.

Answer 2

In D6, putting this in your theme's _preprocess_page() hook should do it:

if (isset($vars['node'])) {
  $edit_or_add = basename($_GET['q']);

  if ($edit_or_add == 'edit' || $edit_or_add == 'add') {
    $vars['template_files'][]='page-cck-' . str_replace('_','-',$vars['node']->type . '-' . $edit_or_add);
  }
  else {
    $vars['template_files'][]='page-cck-' . str_replace('_','-',$vars['node']->type);
  }
}

Then create a page-cck-CONTENT-TYPE.tpl.php, page-cck-CONTENT-TYPE-edit.tpl.php and/or page-cck-CONTENT-TYPE-add.tpl.php and you should be all set. (By the way, I added the cck- on my sites to be overly clear as to what was going on, it's up to you.)