POINT Pts;
RECT WndPos;
HWND hWnd = FindWindow("Shell_TrayWnd", NULL);
while(TRUE){
	Sleep(1);
	GetCursorPos(&Pts);
	GetWindowRect(hWnd, &WndPos);
	if(Pts.x >= WndPos.left && Pts.x <= WndPos.right && Pts.y >= WndPos.top && Pts.y <= WndPos.bottom){
		//Send hover message
	}else{
		//Send non hover message
	}
}