I did get a response from JROX as follows:
admin response by Ryan Dec 22 2009 03:19:30 AM
Integration – eStore WordPress Plug in that uses the PayPal IPN: Please help!
if your estore is already using the notify_url (IPN), you will have to find a way to transport the JROX cookie on the paypal form. normally, we use the ‘custom’ field to transport the cookie, like so:
<input type=”hidden” name=”custom” value=”‘ . $_COOKIE . ‘” />
then on the paypal IPN file of your estore, you add the PHP script:
$JAMIntegrate = file_get_contents(“http://www.mydomainname.com/affiliates/sale.php?amount=”.$_POST.”&trans_id=”.$_POST.”&custom_mid=”.$_POST);
Can you tell me where I should place these pieces of code… what files and what lines?