Problem with defining a classfunction for Linked list

I'm making a object-oriented linked list in c++, and I'm having problems with asigning new value to my head pointer:

#include "Lista.h"
#include <cstddef>
#include <cassert>

LankadLista::LankadLista(): size(0), head(NULL){}

LankadLista::~LankadLista(){
     //while (!KollaLista())
          //remove(1);
}

void LankadLista::LaggTill(int index, dataTyp nyNod)
{
     int nyLangd = ReturElement() + 1;

     Nod *nyPek = new Nod;  
     size = nyLangd;

     nyPek->data = nyNod;

     if (index == 1)
     {    
          nyPek->next = head;
          head = nyPek;
     }
     else
     {
          Nod *prev = SokElement(index-1);
          nyPek->next = prev->next;
          prev->next = nyPek;
     }
}
/*void Tabort(){
}
void Sortera(){
}
void skrivUt(){
}*/
int LankadLista::SokElement(int index)
{
     /*if ((index < 1) || (index > ReturElement()))
          return NULL;
     else
     {
          Nod *cur = head;
          for (int skip = 1; skip < index; ++skip)
               cur = cur->next;
          return cur;
     }*/
}
bool LankadLista::KollaLista() const
{
     return bool(size==0);
}
int LankadLista::ReturElement()
{
     return size;
}

The problem is in the Laggtill(insert) function, head = nyPek. "cannot convert 'LankadLista::Nod*' to 'Nod*' in assignment"
Here is the classfile:

#include <iostream>
using namespace std;

typedef int dataTyp;
typedef struct Nod *pek;

class LankadLista {

public:
     LankadLista();
     ~LankadLista();

     void LaggTill(int index, dataTyp NyNod);
     //void Tabort();
     //void Sortera();
     //void skrivUt();
     int SokElement(int index);
     bool KollaLista() const;
     int ReturElement();

private:

     struct Nod {
          dataTyp data;
          pek next;
     };

     int size;
     Nod *head;

};

I hope someone can help me, thanks.
//Olle