Thanks, I got it working so far, but Ive got some problems.
1. On resizing the window Im crashing but IDK what pointer is invalid
2. I tried hooking GS MessageHandler to handle all the window messages with the gui function:

Code:
typedef LRESULT (CALLBACK *tMessageHandler)(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
tMessageHandler oMessageHandler;

LRESULT CALLBACK hkMessageHandler(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	MessageBoxA(NULL, "LOL", "LOL", MB_OK);

	return oMessageHandler(hwnd, message, wParam, lParam);
}

oMessageHandler = (tMessageHandler)(ev->on_message);
ev->on_message = (EVENT*)hkMessageHandler;


But the MsgBox never pops up.
Please help me frown