how to add text entered in one dialog to another dialog's listbox

:wave: how to add text entered in one dialog to another dialog's listbox

Send a message. For example:
...
#define WM_NEWTEXT WM_USER + 51
...

From the first dialog:
::SendMessage(hSecondDlg, WM_NEWTEXT, (WPARAM)szBuffer, (LPARAM)nSize);

and inf the second dialog you need to write a handler for WM_NEWTEXT

Are these two dialogs part of the same application? Or different ones?