I'm trying to get this to work on Numinix's tableau2 template but I'm not sure where to put the code in tpl_contact_us_default.php because the file is completely custom compared to the default one.

I've added it after <?php echo zen_draw_input_field('should_be_empty', '', ' size="40" id="CUAS" style="visibility:hidden; display:none;" autocomplete="off"'); ?>
but the captcha isn't required so the spam is going through like usual.

Code:
<?php
/**
 * Page Template
 *
 * Loaded automatically by index.php?main_page=contact_us.<br />
 * Displays contact us page form.
 *
 * @package templateSystem
 * @copyright Copyright 2003-2012 Zen Cart Development Team
 * @copyright Portions Copyright 2003 osCommerce
 * @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
 * @version GIT: $Id: Author: DrByte  Sun Aug 19 09:47:29 2012 -0400 Modified in v1.5.1 $
 */
?>
<div class="centerColumn col-lf" id="contactUsDefault">
<h1><?php echo HEADING_TITLE;?></h1>
<span class="required-note"><?php echo FORM_REQUIRED_INFORMATION; ?></span>

<?php echo zen_draw_form('contact_us', zen_href_link(FILENAME_CONTACT_US, 'action=send',($_SERVER['HTTPS'] == 'on' ? 'SSL' : 'NONSSL'))); ?>

<?php
  if (isset($_GET['action']) && ($_GET['action'] == 'success')) {
?>
<!-- 
	/*
	 *  Code changed on: May 26, 2014;
	 * 	Fixed issue: Layout for success message;
	*/
 -->
<div id="contact-form-wrapper">
	<p class="messageStackSuccess mt0"><?php echo TEXT_SUCCESS; ?></p>
	<div class="buttonRow"><?php echo zen_back_link() . zen_image_button(BUTTON_IMAGE_BACK, BUTTON_BACK_ALT) . '</a>'; ?></div>
</div><!--EOF #contact-form-wrapper-->

<!-- 
	/*
	 *  End Code changed on: May 26, 2014;
	*/
-->

<?php
  } else {
?>

<?php if ($messageStack->size('contact') > 0) echo $messageStack->output('contact'); ?>

<?php 
	if (DEFINE_CONTACT_US_STATUS >= '1' and DEFINE_CONTACT_US_STATUS <= '2') { 
		echo '<div class="contact-us-intro">';
			require($define_page);
		echo '</div>';
	} 
?>

<div class="row">
	<?php if (CONTACT_US_STORE_NAME_ADDRESS== '1') { ?>
	<div class="contact-details col-sm-12">
		<address class="contact-info"><?php echo nl2br(STORE_NAME_ADDRESS); ?></address>		
	</div><!--EOF #store-details-wrapper-->
	<?php } ?>

	<div class="contact-form col-sm-12 cf">

		<?php
			// show dropdown if set
			if (CONTACT_US_LIST != ''){
		?>
		<div class="row">
			<div class="col-xs-12">
			<
				<label class="inputLabel" for="send-to"><?php echo SEND_TO_TEXT; ?> <?php echo '<span class="alert">' . ENTRY_REQUIRED_SYMBOL . '</span>'; ?></label>
				<?php echo zen_draw_pull_down_menu('send_to',  $send_to_array, 0, 'id="send-to"'); ?>
				
			</div>
		</div>
		<?php
			}
		?>
		
		<div class="row">
			<div class="col-xs-6">
				<label class="inputLabel" for="contactname"><?php echo ENTRY_NAME; ?> <?php echo '<span class="alert">' . ENTRY_REQUIRED_SYMBOL . '</span>'; ?></label>
				<?php echo zen_draw_input_field('contactname', $name, ' size="40" id="contactname"'); ?>
			</div>
			<div class="col-xs-6">
				<label class="inputLabel" for="email-address"><?php echo ENTRY_EMAIL; ?> <?php echo '<span class="alert">' . ENTRY_REQUIRED_SYMBOL . '</span>'; ?></label>
				<?php echo nmx_draw_email_field('email', ($email_address), ' size="40" id="email-address"'); ?>
			</div>
		</div>

		<div class="row">
			<div class="col-xs-12">
			
				<label class="inputLabel" for="enquiry"><?php echo ENTRY_ENQUIRY . ' <span class="alert">' . ENTRY_REQUIRED_SYMBOL . '</span>'; ?></label>
				<?php echo zen_draw_textarea_field('enquiry', '30', '7', $enquiry, 'id="enquiry"'); ?>
				<?php echo zen_draw_input_field('should_be_empty', '', ' size="40" id="CUAS" style="visibility:hidden; display:none;" autocomplete="off"'); ?>
				<br class="clearBoth" />
				<?php echo recaptcha_get_html(false); ?>
				
			</div><!--EOF #contact-col-right-->
		</div>
		
		<div class="buttonRow back"><?php echo zen_image_submit(BUTTON_IMAGE_SEND, BUTTON_SEND_MESSAGE_ALT); ?></div>
		
	</div><!--EOF #contact-form-wrapper-->

</div>


<?php
  }
?>

</form>


</div>