when you're included php file generates some variables like

$newestmember etc..

Then you can reference to them in the template

So if you have:

<?

$templatesused = "newtemplate";
require("./global.php");

$bla = "123";

eval("dooutput(\"".gettemplate("newtemplate")."\") ;");

?>

Then you can reference to $bla in your template....Or if you have a separate php file which contains $bla and you include this file before evaluating the template you can do exact the same thing...

Evaluate does just evaluating the content of a template as if it was php code...so every $variable in the template is parsed with their corresponding variable...