How to redirect your 404 error to a custom page

[pypo]

Is there a best way in Genesis to redirect all 404 errors to a landing page?

There is this plugin that redirects all 404 errors to the home page. But I want to redirect all 404 errors to a page called "http:/myblog/404-landing-page"

Any advice?

function redirect_all_404s() {
global $wp_query;
if ($wp_query->is_404 ) {
header("Location: ".get_bloginfo('siteurl'),TRUE,301);
}
}
add_action('wp', 'redirect_all_404s');

?>