I want to include a file in $includes[content] is a variable and i want to use an include function.

$includes[content]="
<form action=\"index.php?view=login&action=login&".iif($rid!="","rid=$rid&")."".$url_variables."\" method=\"post\" onSubmit=\"submitonce(this)\">
<input type=\"hidden\" value=\"$returnTo\" name=\"returnTo\">
Some html in php form.
 <-- I want to add include 'sys/CodeGen.php'; function -->
Some more html in php form.

Ends in
</form></div>

";
?>

Nasıl [içerik] içerir arasına eklerim?