php as an html include

Has anyone tried executing php through a html server side include? I'm running php-Nuke, (if you're not familiar its a php/mysql site management tool) which won't allow php to be used in its templates. I thought, what if a ssi processed the php as a cgi, before being called as generated html into one of the php-nuke templates. I'm guessing the include would look something like this: <!--#exec cgi="php.cgi" --> But I haven't been able to get it work, or using other variations of the include tag, within the templates, or just on a page with the include only. Where can I find a resource that goes through the steps of running php as a cgi script. The php manual doesn't have much. Better yet, can anyone tell me how it's done? If php was installed as an apache module, does it have to be recompiled to run php scripts as cgi? There doesn't seem to be a php executable (#! /usr/bin/php) installed with the module version, or its called something other the "php". Greg