Now create a .PHP file with the following code.
$script = file_get_contents($_REQUEST['js']);
$packed = $packer->pack();
Next, bust open the .htaccess and add the following. Note you should have mod_rewrite enabled and mod_rewrite set to ON. If you dont know how to do this, contact your sysadmin or check it out on apache's website.
RewriteRule ^(.+)\.js$ jsProxy.php?js=/$1.js
Need to exclude a file? Simply make it .jsx or some other extension other than .js, the browser doesn't care but mod_rewrite will ignore it.