How can I setup a simple paypal buy now button for suscribing paypal payment. i.e not making just one time payment but to suscribe the user for monthly payment? What variables I need to setup?

How can I setup a transaction so that it becomes successfull only if postal adress of the customer matches to the address which I post to the paypal? What variables I need to setup?

I tried quite some time to find answers of those in paypal documentaion but unfortunately no success after spenting lot of time. I am really short of time to do research on this so I am posting it here. Hopefully it will be easy for someone to answer who is experience in paypal.