"SendMessage" to 3 different processes in C++
I want to send keystrokes to multiple processes. For example, if I press “1”, then I want to send the “1” to 3 "Notepad windows". Frist I want to try to send a keystroke to notepad, but it fails on the HWND:
	

        //HANDLE hWin; 
    	HWND windowHandle = FindWindowA(NULL, "Notepad"); 	//Can’t find a proccess
    
    	//Send a key
    	if( windowHandle ) //This one fails
    	{
    		while(true)
    		{
    			if( GetAsyncKeyState(VK_F12) != 0 )
    			{
    				SendMessageA(windowHandle, WM_KEYDOWN, VK_NUMPAD1, 0); 
    				Sleep(1000); 
    				SendMessageA(windowHandle, WM_KEYUP, VK_NUMPAD1, 0);
    			}
                        Sleep(100);
    		}
    	}

But the "FindWindow" method is not good enough for my program. There is also no way to get 3 different processes with the same name. So how can I make 3 handles to 3 different processes with the same name? And how can I send key’s to the processes?  
"SendMessage" to 3 different processes in C++
===

I want to send keystrokes to multiple processes. For example, if I press “1”, then I want to send the “1” to 3 "Notepad windows". Frist I want to try to send a keystroke to notepad, but it fails on the HWND:
	

        //HANDLE hWin; 
    	HWND windowHandle = FindWindowA(NULL, "Notepad"); 	//Can’t find a proccess
    
    	//Send a key
    	if( windowHandle ) //This one fails
    	{
    		while(true)
    		{
    			if( GetAsyncKeyState(VK_F12) != 0 )
    			{
    				SendMessageA(windowHandle, WM_KEYDOWN, VK_NUMPAD1, 0); 
    				Sleep(1000); 
    				SendMessageA(windowHandle, WM_KEYUP, VK_NUMPAD1, 0);
    			}
                        Sleep(100);
    		}
    	}

But the "FindWindow" method is not good enough for my program. There is also no way to get 3 different processes with the same name. So how can I make 3 handles to 3 different processes with the same name? And how can I send key’s to the processes?  