Index: categories_tag_processor.php
===================================================================
--- categories_tag_processor.php	(revision 14318)
+++ categories_tag_processor.php	(working copy)
@@ -270,8 +270,12 @@
 			unset($params['direct_link']);
 		}
 
+		if ( isset($this->Application->structureTemplateMapping['id:' . $category_id]) && preg_match('/external:(.*)/', $this->Application->structureTemplateMapping['id:' . $category_id], $rets) ) {
+			// external url
+			return $rets[1];
+		}
+
 		unset($params['cat_id'], $params['module']);
-
 		$new_params = Array ('pass' => 'm', 'm_cat_id' => $category_id, 'pass_category' => 1);
 		$params = array_merge_recursive2($params, $new_params);