Welcome to WebmasterWorld sarfarazali meghani. If I understand correctly, when someone comes to m.example.com/page1.html, you would want them to be redirected to example.com/page1.html and so on? Would this be for non mobile visitors only?
Just trying to get a handle on what you are looking to accomplish.
It's exactly the same code that you're already using to redirect the "wrong" forms of your domain name-- typically with/without "www." Capture the whole request and attach it to a fresh request under a different (sub)domain name.
Frankly your much bigger problem is UA detection. It may be simpler to detect the non-mobile user agents. Anything left over is then either a robot or a mobile. You also need a way for the human user to override the redirect if that's their individual preference --or if UA detection makes a mistake, which is bound to happen sooner or later.