SetWindowsHookEx

// test.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
typedef LRESULT (CALLBACK *MYPROC)(int, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
    // TODO: Place code here.
  HINSTANCE hinstLib;
  MYPROC ProcAdd;

  hinstLib = LoadLibrary("C:\\tmp\\dll_test\\hook\\Debug\\hook.dll");

  // If the handle is valid, try to get the function address.
  if (hinstLib != NULL)
  {
    ProcAdd = (MYPROC) GetProcAddress(hinstLib, "MyFunc");

    // Do add operation
    // If the function address is valid, call the function.
    if (ProcAdd)
      (ProcAdd)(0,0,0);

//    SetWindowsHookEx(WH_MOUSE, ProcAdd, hinstLib, 0);

    // Free the DLL module.
    FreeLibrary(hinstLib);
  }
    return 0;
}

// hook.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "hook.h"

BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
        case DLL_PROCESS_ATTACH:
      MessageBox(0, "Dll load in procces!", "OK", MB_OK);
      break;
        case DLL_THREAD_ATTACH:
        case DLL_THREAD_DETACH:
        case DLL_PROCESS_DETACH:
      MessageBox(0, "Dll unload from procces!", "OK", MB_OK);
      break;
    }
    return TRUE;
}

//extern "C" __declspec(dllexport)
LRESULT CALLBACK MyFunc(int nCode,
                        WPARAM wParam,
                        LPARAM lParam)
{
  MessageBox(0, "Hello from MyFunc!", "OK", MB_OK);
  return 1;
}