I've added the code to define_main_page.php and it works fine but what I need to know is what bits of code do I need to change (in the following line of code - <?php require($template->get_template_dir('test.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/test.php');?>)

in order to get my page called shownews.php to display on the main page? Sorry if I'm not making much sense but it's confusing me?!