2
is it inside modules folder or in main folder ?
if it is index page of custom module, you can set the permissions from groups page.
if this page in root folder, use this code:
include("path/to/mainfile.php");
include(XOOPS_ROOT_PATH."/header.php");
if ( !is_object($xoopsUser) ) {
redirect_header("indx.php",0);
exit();
} else {
echo "My html content";
}
include(XOOPS_ROOT_PATH."/footer.php");
?>