[Reasen]

Me auto-respondo, Lo solucioné de esta manera:

Código Delphi [-]
  function GetText(XHand : THandle):string;
var textlength:integer;
  text:PChar;
begin
  textlength:=SendMessage(XHand,WM_GETTEXTLENGTH,0,0);
  if textlength=0 then Result:='Empty' else
  begin
    getmem(text,textlength+1);
    SendMessage(XHand,WM_GETTEXT,textlength+1,Integer(text));
    Result:=text;
    freemem(text);
  end;
end;