Topic: Paypal Buttons Logic

I want to build a service that accepts donations and I want to use paypal to do it.
Here's the logic:

- The person add the paypal account info into her profile
- I generate a payment button to each person dynamically.
- When this person receives a payment, that person should receive 95% of the amount on her paypal account and I should receive 5% of the amount at my service's paypal account.

How can I do that?