Hi. hehehe good point about the 3th slash. Without that, the error.log shows:
2013/11/18 23:13:46 [error] 66112#0: *2 open() "/usr/local/html/specialService/aserverthatlistens.com/serviceToCall" failed (2: No such file or directory), client: 127.0.0.1, server: localhost, request: "POST /specialService/aserverthatlistens.com/serviceToCall HTTP/1.1", host: "localhost:8383"