The phpwcms support forum will help to find answers to your questions. The small but strong community is here since more than 10 years.
https://forum.phpwcms.org/
"include/inc_fron/front.func.inc.php"type="application/rss+xml" title="RSS" href="'.PHPWCMS_URL.'rss.php">'."\n";
// RSS feed link based on structure (category) ID
$search[12] = '/\[RSS (\d+)\](.*?)\[\/RSS\]/';
$replace[12] = '<a href="rss.php?rssfeed=$1" target="_blank">$2</a>';
// RSS feed link based on structure (category) ALIAS
$search[13] = '/\[RSS (\w+)\](.*?)\[\/RSS\]/';
$replace[13] = '<a href="rss.php?$1" target="_blank">$2</a>';