c++ How to return a pointer to a struct located inside a template class

Question

I have some template clases, diferents types of list really, and i need to implement a method called "traduct" that has to return a pointer to a certain element in the list

traduct applied to this class should retorn a pointer to the struct

namespace std
{
//typedef struct PosicionS;

template <typename Type> class ListaPosicionada_DoubleLinked
{
    private:
        struct Posicion
        {
            Type elemento;
            Posicion* anterior;
            Posicion* siguiente;

    public:
        Posicion( const Type& elemento, Posicion* next = nullptr, Posicion* back = nullptr  )
            : elemento(elemento)
            , anterior(back)
            , siguiente(next)
        {}
};

and here is the declaration traduct located in the main:

template <template <typename> class Lista, typename Type, struct posicion>
Lista<Type>::posicion& traduct( Type& elemento )
{
    ...
}

a get this errors after compilation:

error: 'struct posicion' is not a valid type for a template non-type parameter
template <template <typename> class Lista, typename Type, struct posicion>
                                                                 ^
error: need 'typename' before 'Lista<Type>::posicion' because 'Lista<Type>' is a dependent scope
Lista<Type>::posicion traducir( Type& elemento )
^

what is the correct form to return a pointer of the struct, should I implement a typedef to do the trick?