Wordpress Auto Thumbnail from Post

Hello, I need to customized the functions in my theme to make it auto generate thumbnails from posts (the first image) that is not local, it`s referenced in a url. I have the code, I just need to make it work with this theme. My website is: [login to view URL] As you can see, I have tried using the Auto Post Thumbnail plugin but it generated the thumbnail from the second picture (that is referenced localy) not the first one from the url. //////////////////////////////////////////////////////////////////////////////// // Get Featured Post Image //////////////////////////////////////////////////////////////////////////////// function get_featured_slider_image() { global $post, $posts; $first_img = ''; ob_start(); ob_end_clean(); $output = preg_match_all('//i', $post->post_content, $matches); $first_img = $matches [1] [0]; if(empty($first_img)){ //Defines a default image $img_dir = get_bloginfo('template_directory'); $first_img = $img_dir . '/images/[login to view URL]'; } return $first_img; } //////////////////////////////////////////////////////////////////////////////// // Get Post Image //////////////////////////////////////////////////////////////////////////////// function get_post_image() { global $post, $posts; $first_img = ''; ob_start(); ob_end_clean(); $output = preg_match_all('//i', $post->post_content, $matches); $first_img = $matches [1] [0]; if(empty($first_img)){ //Defines a default image $img_dir = get_bloginfo('template_directory'); $first_img = $img_dir . '/images/[login to view URL]'; } return $first_img; } //////////////////////////////////////////////////////////////////////////////// // Get Featured Category Image //////////////////////////////////////////////////////////////////////////////// function get_featcat_image() { global $post, $posts; $first_img = ''; ob_start(); ob_end_clean(); $output = preg_match_all('//i', $post->post_content, $matches); $first_img = $matches [1] [0]; if(empty($first_img)){ //Defines a default image $img_dir = get_bloginfo('template_directory'); $first_img = $img_dir . '/images/[login to view URL]'; } return $first_img; }