When a buyer submits a payment through Paypal, Paypal returns an IPN (Instant Payment Notification) to Warrior Plus. This IPN lists a lot of information about the seller and buyer, in order to ensure the correct order is sent to the correct buyer. The IPN returns such information as the buyer's name and email address.
When creating your listing, there is a box that will allow you to forward the IPN to another address. This address could be the address of the script you wrote.
If you need to keep your own records of purchases, or integrate with some other third party program, you can write a script that will take this information and put it in a format you can use. You can then have the script send along the relevant pieces of information to email lists, a database that you have access to, or whatever else you may need the information for.
You can find more information on third party integration here.