<?php

function mid($start, $end, $str) {
    $str = substr($str, strpos($str, $start) + strlen($start));
    return substr($str, 0, strpos($str, $end));
}

$data = "cursor:pointer; background:url(http://maps.google.com/staticmap?center=38.7376583333,-9.1658583333&maptype=satellite&zoom=14&size=300x300&key=ABQIAAAAvQ9c8pqKsi8K2dzb7UM9MhS13VDmd70a9rmDETSCgg2iXt3XnhQSnX4vFKfWO-3vdWNV5HHBnSLWLQ&sensor=true&hl=pt) no-repeat";

print_r(mid('?center=', '&', $data));

?>

38.7376583333,-9.1658583333