using php in banners?

[itinfraco]

Hi, I'm trying to include a dynamic banner (zc 1.3.9) which will display featured product images using a slider by including the following text in Banner Manager, HTML text:

<br />
<?php
  $zc_show_featured_products = false;
  include(DIR_WS_MODULES . zen_get_module_directory(FILENAME_FEATURED_SLIDER_PRODUCTS));

?>

<div id="wrapper">
	<div class="slider-wrapper theme-orman" style="margin:auto">
    <div class="ribbon"></div>
		<div id="slider">


<?php
 if (is_array($list_box_contents) > 0 ) {
 for($row=0;$row<sizeof($list_box_contents);$row++) {
    $params = "";
    //if (isset($list_box_contents[$row]['params'])) $params .= ' ' . $list_box_contents[$row]['params'];
?>

<?php
    for($col=0;$col<sizeof($list_box_contents[$row]);$col++) {
      $r_params = "";
      if (isset($list_box_contents[$row][$col]['params'])) $r_params .= ' ' . (string)$list_box_contents[$row][$col]['params'];
     if (isset($list_box_contents[$row][$col]['text'])) {
?>
    <?php echo $list_box_contents[$row][$col]['text']; ?>
<?php
      }
    }
?>
		</div>
	</div>
</div>
<?php
  }
}
?>

However, the php isn't interpreted and displays as html - note that the code works fine when displayed as the main page but I want it removed from there so it won't be edited in error.

Any ideas?