Paypal API for adaptive payments

Hello, I need help with the Paypal API for adaptive payments. This is what I want to do on my service, example: Client A accepts to pay $100 if a work he wants is done is made before a deadline (a few days at best) so: - $100 hold is placed in his Paypal account. Few hours after a member B of our service accept to make this proposed job, so if our commission is 20% for example, then: - B tell us his Paypal email (not know when when the Client A placed the order) - B receives $80 from the money held in the Paypal account of A - We receive $20 from A in our Paypal account And if nobody wants to make his job before the deadline then the $100 hold is released and no payment is made to anyone. I would like the syntax of all the REST API needed to perform each step. In addition it will be great to have the code to perform these steps in classic ASP VBScript (prefered) or C# .NET.