How to dispatch urls into several routers?

I would like to know what is the proper way to achieve the following :
In one main router file :

scope "/", MyApp do
    "/subScope1" call_SubScope1
    "/subScope2" call_SubScope2
    ...
end  

and in different “subrouter” files, one for each SubScopei:

scope "/", MyApp do
    get "/action1" controllerSubScopei, :action1
    get "/action2" controllerSubScopei, :action2
    ...
end  

I looked into the forward function, which looked lie the way to achieve this (even though I’m not sure of that), but was unable to use it so far : when I try to create another router Module, with these three lines :

  use Phoenix.Router
  import Plug.Conn
  import Phoenix.Controller

I get an error msg telling me that init function is not defined.

Well, my mistake came from a typo. Things seem to actually work as I tried them. The following:

scope "/", MyApp do
    forward "/subScope1", SubScope1
    forward "/subScope2", SubScope2
    ...
end  

works fine, with separated files as follow:

defmodule MyApp.SubScopei do
  use MyApp, :router

  scope "/", MyApp do
    get "/action1", controllerSubscopei, :action1
    get "/action2", controllerSubscopei, :action2
  end

end