C++ callback stuff using static methods declared in header

//main.cpp
#include "A"
void Handler(int val);
void Handler(int val) 
{
  printf("%d", val); //should display 5
}
int main()
{
   A fnc;
   fnc.execute(&Handler); //no matching function for call to (void (::*)(int))|
}
//A.h
public:
void execute(void **something(int val));

//A.cpp
void execute(void **something(int val))
{
   //call Handler()
   something(5);
}