adding box2d to new wp8 project

Please tell me how to add box2d to a template project in the template folder of cocos2d-x dir. I am using cocos2d-x 2.2.
My template project is working fine but when i try to add box2d project to the existing project then it is not recognizing the included box2d file.

Please help i am working on the game and need to fix this as soon as possible. Currently i am writing code in win32 version…

Thanks