Custom Requests

I have successfully got custom requests to work as far as the content of the request, the thank you url with unique CGI strings but the destination URL seems to be a problem. I understand that if someone accepts a request there is a call to the site and the destination is then sent to FB at the same time as deleting the request. Would there be any way to store a unique request db record for each customised request so that customised destination url could be used?

Code below should give you an idea of what I am trying to achieve

foreach ($result as $row) {
$hash=md5(time().$gu_id.$row);
echo '
var jfbcRequests = Object.prototype.toString.call(jfbcRequests) == "[object Array]" ? jfbcRequests : [];
var jfbcRequest = new Object;
jfbcRequest.title = "Send '. $row .' to your friends";
jfbcRequest.message = "'. $row .'";
jfbcRequest.destinationUrl = "treasure.blackjack.com/receiveitem?req='.$hash.'";
jfbcRequest.thanksUrl = "treasure.blackjack.com/sendconfirm?req='..._id.'&item_id='.$row.'";
jfbcRequests.'] = jfbcRequest;
';

Thanks Url currently saves a record of the request to stop more than 1 request per day and that is working fine