I'm not sure what data exactly you are looking to reference. What do you mean by "the requests from the cart confirm process?". They may not be available from IPN. IPN only includes the IPN variables paypal passes. You can't add your own (although you can set theirs to your own values). What value exactly are you looking to record?
It looks like the code creates a file:
That will list all of the available ipn_data values... you might want to check that to see if the information you need is listed.