Dear jasonF ,
It's easy, just put this code to your file:
<?php
the_ddlayout('YOUR-LAYOUT-SLUG’);
?>
you also, can use it inside wordpress loop:
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<?php the_ddlayout('YOUR-LAYOUT-SLUG’); ?>
<?php endwhile; ?>
Please let me know if you are satisfied with my answer and if I can help you with any other questions you might have.
Regards,
Gen.