I thought this one will be a doodle to find in google, as many you us UI and script writers would need to do this on a day to day basis, that is include a bit of peice of PHP code snippet(.php) into a Smarty Template (.tpl).  I realized that easier/popular  your query, even more difficult to find the exact answer…   a million search results but most of them reffered to “file” includes in Smarty … which has the following syntax

    {include file=”include/header.php”}

This actually inlcuded the file fine but as text , What I wanted was the result of  included file .(Note the above is used include template inside a template file). Finally with a bit persiverance …. I stumbled across a slighty modified syntax, which was the answer to my requirement … so here it is… if you havn’t found  one already

{include_php file=”include/header.php” }