[Light Speed]

What can I do to the code to make it work to allow caching?

The mod code looks like this:

{* ==================== Sub categories mod start *} 
{section name=cat_num loop=$subcategories} 
{ if %cat_num.first% } 
{if $tmp} [img]{if $current_category.icon_url}{$current_category.icon_url}{else}../icon.php?categoryid={$cat}{/if}[/img] {/if}
<table width="75%" border="0" align="center" cellpadding="5" cellspacing="0"> 
{/if} 
{ if %cat_num.index% is div by 3} 
<tr> 
{/if} 
<td align="center" valign="top"> 
<a href="home.php?cat={ $subcategories[cat_num].categoryid }"> 
[img]../icon.php?categoryid={$subcategories[cat_num].categoryid}[/img] 

 

<font class="ItemsList">{ $subcategories[cat_num].category|escape }</font> 
{if $config.Appearance.count_products eq "Y"} 
? ?{if $subcategories[cat_num].product_count}
 
? ?({ $subcategories[cat_num].product_count } Products) 
? ?{elseif $subcategories[cat_num].subcategory_count}
({ $subcategories[cat_num].subcategory_count } Subcategories)</a> 
? ?{/if} 
{/if} 

</td> 
{ if %cat_num.last% } 
</tr> 
</table> 
{/if} 
{/section} 

{* ==================== Sub categories mod end *} 

So they are calling the subcat icons with this line:
[img]../icon.php categoryid={$subcategories[cat_num].categoryid}[/img]


And I want the browser to cache the image so I guess I need the code to be written to the page as a true url to the image.


How can I do that?
Do have to make a new tpl file for the sub cat icons that functions like the product_thumbnail.tpl file? Is that what generates the true urls for the thumbnails? How would I implement that?