Create featured pages in another page (ex. About)

Hello everyone.
I would like to set 3 featured pages in a page other than the front (ex. About). I’ve searched the forum and I read I have to apply some filters:

add_filter ( 'tc_show_fp' , 'my_show_fp');
function my_show_fp($show_fp) {
	$show_fp = ( $show_fp || is_page( 42 ) ) ;
	return $show_fp;
}

Because I’m a newbie, can someone explain the code above with the filters in which file do I apply it? Or if there’s another simpler way to do this.
Thanks in advance.