I have PayPal express setup on my Magento 1.8 instance however I would like to pass additional information through to Paypal eg an account number. Looking at https://developer.paypal.com/docs/classic/api/merchant/SetExpressCheckout_API_Operation_NVP/ it seems the field PAYMENTREQUEST_n_CUSTOM might be useful but not entirely too sure
Please could someone advise if this is possible
