Linking to a Cell in a Google Spreadsheet

link_to_cell.php

$url = $_REQUEST["url"];
$key = $_REQUEST["key"];
$anchor = $_REQUEST["anchor"];

$html = file_get_contents($url);
$output = str_replace($key, "<a name="$anchor"></a>$key", $html);
$output = str_replace("href='/", "href='https://docs.google.com/", $output);

header("Content-Type: text/html");
echo $output;