How to paint into another windows' caption bar

Problem/Question/Abstract:

How to paint into another windows' caption bar

Answer:

If you can get a handle to a Windows object, generally if it supports a WM_SETTEXT message (most windows do), then you can change the caption. The example below does just that:

procedure Form1.Button1Click(Sender: TObject);
begin
  WinExec('notepad.exe', SW_SHOWNORMAL);
end;

procedure Form1.Button2Click(Sender: TObject);
var
  hChild: HWND;
  strNewTitle: string;
begin
  hChild := FindWindow(nil, 'Untitled - Notepad');
  if (hChild <> NULL) then
  begin
    strNewTitle := ' Funny name ';
    SendMessage(hChild, WM_SETTEXT, 0, LPARAM(PChar(strNewTitle)));
  end;
end;

Note that this was written in D5 and the FindWindow(...) function can be a little ornery in some instances (like case sensitivity and precise text makeup, see example).