Hello poboy,
If you would still like to create a link for your client, then in your subcategories.tpl locate your <a href> links to your home.php section.
Please put them BEFORE your {section} code:
{if $location.1 ne ""}
{assign var="new_window" value="`target="_blank" `"}
{/if}
Please note the backticks within value.
In your <a href> link do:
<a {$new_window}href="home.php?cat={$cat}">
*sorry I might have not gotten the syntax correct, it's from memory.*
Not the most elegant method, but I think it'll work.