[NumLock]

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  h: THandle;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  h:=CreateWindow('EDIT', 'bla', WS_CHILD, 10, 10, 100, 20, Handle, 0, HInstance, nil);
  // lpWindowName: PChar = bla
  ShowWindow(h, SW_SHOW);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  buf: array [0..$ff] of Char;
  l: Integer;
begin
  l:=GetWindowText(h, buf, $100);
  Edit1.Text:=Copy(buf, 1, l); // = bla
end;

end.