.Net ThreadPool

Question

Is it possible to get the return Address of a thread, This is the scenario. I have a main thread, from the main thread am calling a functionA synchrously..I do some processing on the input parameter the I call one more functionB asynchrnously. I process something on the input parameter & need to return the value then functionA does something on the value returned from the FunctionB. Its something like below

Main 11 --> FuncA +1 ==> FuncB +2
17           <==== +3 <====
(for all calls)
I have achieved it on Threadpool using Action/delegate, Interface, Taskparallel library, Async Result. It should have only 3 Function-No blocking at any point. Is it possible by another means??