How to edit product listing image link code?

[marksu]

I have a own css that I can make a hoower popup, meaning that when cursor is on top of image it is automatically displayes in large size as popup.
When hoower of image enlarged image dissapears.

What I need is to edit the product listing's image link code.
I would need direction where about the code is defined for the image in product listing.

Note that I am using module "Column Layout Grid for Product Listing".

I presume I need to look in file tpl_modules_product_listing.php

There is following code (how to look further?)
<?php
/**
* load the list_box_content template to display the products
*/
if (PRODUCT_LISTING_LAYOUT_STYLE == 'columns') {
require($template->get_template_dir('tpl_columnar_display.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_columnar_display.php');
} else {// (PRODUCT_LISTING_LAYOUT_STYLE == 'rows')
require($template->get_template_dir('tpl_tabular_display.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_tabular_display.php');
}
?>

marksu

[marksu]

Any succestion on where to edit to create my custom product image with link on product list.

marksu