That would be something like this:
{foreach from=$categories item=c}
{if $c.order_by gt 200 and $c.order_by lt 300}
<div class="CategoriesList"><a href="home.php?cat={$c.categoryid}" class="VertMenuItems">{$c.category}</a></div>
{/if}
{/foreach}
That will show categories with a POS between 200 and 300.