hmm, very good question! being adopted myself, thats 1 thing I never really thought about....If you know info on birth father, I would imagine, get a lawyer, or there is bound to be some kind of local agencys, or types of services that you could contact before contacting a lawyer first, but surely to delve deep into the aspect of your question, you WILL HAVE TO get legal representation to "properly" do what you are wondering about! I mean you are wanting to LEGALLY RECLAIM, so, you need LEGAL REPRESENTATION! Take care! & DO GET A LAWYER! ;)