C / C++ / MFC

1. Store the preselected id in a member variable.
   
2. Override the handler for "mouse on new menu item" (not WM_MENUSELECT) and clear the member variable.
   
3. In the OnDrawItem() override, draw the item as selected if its id matches the member variable's value (if non-zero). If the member variable is zero (i.e. has been cleared), just call the base class OnDrawItem().

void CYourView::OnSomeParticularEvent()
{
  CYourDlg dlg;
  if(dlg.DoModal()==IDOK){
    // use dlg.m_str (for instance, to store it in your
    // CDocument-derived class.)
  }
}

BOOL MyAppClass::InitInstance(void)
{
	if (IsAppAlreadyRunning() == TRUE)
	{
		return (FALSE);
	}

...

	return (TRUE);
}


boolean MyAppClass::IsAppAlreadyRunning(void)
{
	// Determine if application already exists...
	if (OpenMutex(MUTEX_ALL_ACCESS, FALSE, UNIQUE_APPLICATION_MUTEX_STRING) != NULL)
	{
		AfxMessageBox(_TEXT("Error! Application is already running, cannot start another instance."), MB_ICONEXCLAMATION);
		return (TRUE);
	}

	CreateMutex(NULL, FALSE, UNIQUE_APPLICATION_MUTEX_STRING);

	return (FALSE);
}