You can include it via a URL and send the info via GET, or create a function in the included file to receive the variables, then include that file and fire the function from the calling file:
i.e.:
Original file
<?php
// Do some stuff here
include_once('include_me.php');
doInclude($var1, $var2, $var3);
?>
include_me.php
<?php
function doInclude() {
$vars = func_get_args();
}
// Do something with the vars....