How can i display custom post types on a 'page' post type?

Question

what is the code i have to put in the modifyed 'page' post type template?

Answer 1

Easy: modify the query... (and add some comment on top to make a template out of this...)

$query_default = new WP_Query( array(
     'orderby'      => 'menu_order'
    ,'order'        => 'ASC'
    ,'post_type'    => 'custompost' // THIS IS WHAT YOU'RE SEARCHING FOR
    ,'post_status'  => 'publish'
) );
    if ( $query_default->have_posts() ) :

        while ( $query_default->have_posts() ) : $query_default->the_post();

        endwhile;

    else : // else; no posts
        _e( 'Nothing published so far.', TEXTDOMAIN_CONSTANT );
    endif; // endif; have_posts();

    wp_reset_query();

Answer 2

If you look at the Custom Fields page on WordPress codex, you can see the functions for Custom fields.

The "Template Tags" are the functions you generally use on your template:

• get_post_custom() - Returns a multidimensional array with all custom fields of a particular post or page.
• get_post_custom_values() - This function is useful if you wish to access a custom field that is not unique, i.e. has more than 1 value associated with it
• get_post_custom_keys() - Returns an array containing the keys of all custom fields of a particular post or page.

Follow the links to each function to see examples on how to use them.

UPDATE: Ok, now I understand. You should try to add as many details as possible in your question for us to understand. As kaiser says, you should create a loopand add 'post_type' => 'custompost' to get the posts from that custom type. You can use the get_posts() function for this too.