Глобальный хук. Довести до ума

#include <iostream.h>
#include "GH.h"
 
HHOOK hook;
HINSTANCE hin;
 
int APIENTRY DllMain (HINSTANCE hInstance, DWORD fdwReason, PVOID pvReserved){
    switch (fdwReason)
    {
        case DLL_PROCESS_ATTACH :
            hin = hInstance ;
            break ;
    }  
    return TRUE ;
}
 
 
extern "C" __declspec(dllexport) void Pr()
{
    cout<<"Works"<<endl;
}
 
extern "C" __declspec(dllexport) bool TurnON()
{
    cout<<"Hook ON"<<endl;
    hook = SetWindowsHookEx(WH_CALLWNDPROC, HookProc,hin, NULL);
    return true;
}
 
LRESULT CALLBACK HookProc( int nCode, WPARAM wParam,LPARAM lParam)
{
    if( nCode == HC_ACTION )
        cout<<"Action"<<endl;
    return CallNextHookEx(hook, nCode, wParam, lParam);
}

#include <windows.h>
#include <iostream.h>
#include <conio.h>
 
bool(*F)();
int main()
{
    HINSTANCE h;
 
    h = LoadLibrary("GH.dll");
    if( h != NULL )
        cout<<"Loaded"<<endl;
    else
    {
        cout<<"Cannot load"<<endl;
        exit(0);
    }
 
    F = (bool (*)())GetProcAddress(h, "TurnON");
    F();
    getch();
    FreeLibrary(h);
    return 0;
}

LRESULT CALLBACK HookProc( int nCode, WPARAM wParam,LPARAM lParam)
{
    MSG * st = (MSG*)lParam;
    if( nCode == HC_ACTION )
        if( st->message== WM_KEYDOWN )
        {
            st->wParam = 0x42;
            //PostMessage(st->hwnd, st->message, (WPARAM)0x42, (LPARAM)st->lParam); 
            //PostMessage(st->hwnd, WM_KEYUP, (WPARAM)0x42, (LPARAM)st->lParam); 
        }
    else
    {
        //MessageBox(NULL, "BAD", "ON", 0);
        return CallNextHookEx(hook, nCode, wParam, lParam);
    }
    return CallNextHookEx(hook, nCode, wParam, lParam);
}