Hello, nobody1985, you wrote: N> I.e. except how to cause CComboBox:: AddString other methods to fill the drop down list is not present? N> I with MFC did not work for a long time, but like there it was possible static lines directly in the visual designer of a Visual Studio in a combo-boxing to hammer. Though can and I am mistaken. It is possible. But very few people uses it. We begin that application can store in itself an array of any objects, and in a combo only its reflection then outside elements lead to unpredictable operation. And if application is valid can the left elements easier to add them through CB_ADDSTRING or other messages. That is, I at first would check up, whether it can accept generally a new line. It is possible to try to send at first SendMessage though from other process (CB_ADDSTRING <WM_USER), beforehand peeping HWND in a C ++ to be convinced that collapses nothing. SendMessageW ((HWND) 0x2047A, CB_ADDSTRING, 0, (LPARAM) L "Test"); //0x2047A - the combo If does not collapse, as the permanent decision I can offer which would create , and hung up SetWindowsHookEx on it UI , in appearance of the necessary combo and to substitute a content.