Thx a lot silafu, works like a charme! ??
For anyone interested in the whole code, here is how I implemented it:
<?php
$variable = get_post_meta($post->ID, 'ItemTag', true);
//The Query
query_posts(array('tag' => $variable));
//The Loop
if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
<?php include(TEMPLATEPATH . '/custom-mini-product.php'); ?>
<?php endwhile; else:
endif;
//Reset Query
wp_reset_query();
?>