Coding a function to copy a linked-list [C++]

I need to implement an auxilliary function, named copyList, having one parameter, a pointer to a ListNode. This function needs to return a pointer to the first node of a copy of original linked list. So, in other words, I need to code a function in C++ that takes a header node of a linked list and copies that entire linked list, returning a pointer to the new header node. I need help implementing this function and this is what I have right now.

Listnode *SortedList::copyList(Listnode *L) {
 
     Listnode *current = L;  //holds the current node
 
     Listnode *copy = new Listnode;
     copy->next = NULL;
 
     //traverses the list
     while (current != NULL) {
        *(copy->student) = *(current->student);
        *(copy->next) = *(current->next);
 
         copy = copy->next;
         current = current->next;
     }
     return copy;
 }
 

Also, this is the Listnode structure I am working with:

struct Listnode {    
   Student *student;
   Listnode *next;
 };
 

Note: another factor I am running into with this function is the idea of returning a pointer to a local variable.

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