Ocultar una categoría del bloque de categorías sin desactivarla

Buenas tardes, me gustaría ocultar una de las categorías en el bloque de categorías que aparece a la izquierda en Prestashop pero sin desactivarla, de forma que pueda enlazar a la misma desde otras vías.

He leído en otros foros que lo que hay que incluir es esto: AND c.id_category NOT IN (18) *18 es la categoría que quiero ocultar. ¿Dónde se supone que debo insertarlo?

public function hookLeftColumn($params)
{
$this->setLastVisitedCategory();
$phpself = $this->context->controller->php_self;
$current_allowed_controllers = array('category');

if ($phpself != null && in_array($phpself, $current_allowed_controllers) && Configuration::get('BLOCK_CATEG_ROOT_CATEGORY') && isset($this->context->cookie->last_visited_category) && $this->context->cookie->last_visited_category)
{
$category = new Category($this->context->cookie->last_visited_category, $this->context->language->id);
if (Configuration::get('BLOCK_CATEG_ROOT_CATEGORY') == 2 && !$category->is_root_category && $category->id_parent)
$category = new Category($category->id_parent, $this->context->language->id);
elseif (Configuration::get('BLOCK_CATEG_ROOT_CATEGORY') == 3 && !$category->is_root_category && !$category->getSubCategories($category->id, true))
$category = new Category($category->id_parent, $this->context->language->id);
}
else
$category = new Category((int)Configuration::get('PS_HOME_CATEGORY'), $this->context->language->id);

$cacheId = $this->getCacheId($category ? $category->id : null);

if (!$this->isCached('blockcategories.tpl', $cacheId))
{
$range = '';
$maxdepth = Configuration::get('BLOCK_CATEG_MAX_DEPTH');
if (Validate::isLoadedObject($category))
{
if ($maxdepth > 0)
$maxdepth += $category->level_depth;
$range = 'AND nleft >= '.(int)$category->nleft.' AND nright nright;
}

$resultIds = array();
$resultParents = array();
$result = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS('
SELECT c.id_parent, c.id_category, cl.name, cl.description, cl.link_rewrite
FROM `'._DB_PREFIX_.'category` c
INNER JOIN `'._DB_PREFIX_.'category_lang` cl ON (c.`id_category` = cl.`id_category` AND cl.`id_lang` = '.(int)$this->context->language->id.Shop::addSqlRestrictionOnLang('cl').')
INNER JOIN `'._DB_PREFIX_.'category_shop` cs ON (cs.`id_category` = c.`id_category` AND cs.`id_shop` = '.(int)$this->context->shop->id.')
WHERE (c.`active` = 1 OR c.`id_category` = '.(int)Configuration::get('PS_HOME_CATEGORY').')
AND c.`id_category` != '.(int)Configuration::get('PS_ROOT_CATEGORY').'
'.((int)$maxdepth != 0 ? ' AND `level_depth` context->customer->id))).')
)
ORDER BY `level_depth` ASC, '.(Configuration::get('BLOCK_CATEG_SORT') ? 'cl.`name`' : 'cs.`position`').' '.(Configuration::get('BLOCK_CATEG_SORT_WAY') ? 'DESC' : 'ASC'));
foreach ($result as &$row)
{
$resultParents[$row['id_parent']][] = &$row;
$resultIds[$row['id_category']] = &$row;
}

$blockCategTree = $this->getTree($resultParents, $resultIds, $maxdepth, ($category ? $category->id : null));
$this->smarty->assign('blockCategTree', $blockCategTree);

if ((Tools::getValue('id_product') || Tools::getValue('id_category')) && isset($this->context->cookie->last_visited_category) && $this->context->cookie->last_visited_category)
{
$category = new Category($this->context->cookie->last_visited_category, $this->context->language->id);
if (Validate::isLoadedObject($category))
$this->smarty->assign(array('currentCategory' => $category, 'currentCategoryId' => $category->id));
}

$this->smarty->assign('isDhtml', Configuration::get('BLOCK_CATEG_DHTML'));
if (file_exists(_PS_THEME_DIR_.'modules/blockcategories/blockcategories.tpl'))
$this->smarty->assign('branche_tpl_path', _PS_THEME_DIR_.'modules/blockcategories/category-tree-branch.tpl');
else
$this->smarty->assign('branche_tpl_path', _PS_MODULE_DIR_.'blockcategories/category-tree-branch.tpl');
}
return $this->display(__FILE__, 'blockcategories.tpl', $cacheId);
}

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