Windows Media Player in C++ Application

Question

I am writing small application which can video in Windows Media Player.I need to resize it on full screen, but i cannot do it like that:

int main(void)
{
    char szPath[] = "C:\\WindowsApi\\WindowsApi\\GandalfSax.wmv";//Path to video

    HINSTANCE hRet = ShellExecute(
        NULL, 
        "open",       
        szPath,      
        NULL,        
        NULL,        
        SW_SHOW|SW_MAXIMIZE);//Or SW_SHOWMAXIMIZED     
    return 0;
}

But this approach do not work. I think that Windows Player do not handle this flag. I do not know how can i do it in diffrent way. (The Microsoft Documentation suggest to use ATL, but i use Express version).