unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    RichEdit1: TRichEdit;
    procedure FormCreate(Sender: TObject);
  private
    procedure WMNotify(var AMessage: TWMNotify); message WM_NOTIFY;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

type
  PNMMsgFilter = ^TNMMsgFilter;
  TNMMsgFilter = packed record
    nmhdr: TNMHdr;
    msg: UINT;
    wParam: WPARAM;
    lParam: LPARAM;
  end;

procedure TForm1.WMNotify(var AMessage: TWMNotify);
var
  KeyMessage: TWMKey;
  ShiftState: TShiftState;
begin
  if AMessage.NMHdr^.code = EN_MSGFILTER then
  begin
    AMessage.Result := 0;

    if PNMMsgFilter(AMessage.NMHdr)^.msg = WM_KEYDOWN then
    begin
      TMessage(KeyMessage).Msg := PNMMsgFilter(AMessage.NMHdr)^.msg;
      TMessage(KeyMessage).WParam := PNMMsgFilter(AMessage.NMHdr)^.wParam;
      TMessage(KeyMessage).LParam := PNMMsgFilter(AMessage.NMHdr)^.lParam;
      ShiftState := KeyDataToShiftState(KeyMessage.KeyData);

      if ShiftState = [ssCtrl] then
      begin
        if (KeyMessage.CharCode = VK_TAB) or (KeyMessage.CharCode = $45 {E}) or
          (KeyMessage.CharCode = $4C {L}) // etc.
        then
          AMessage.Result := 1;
      end
      else
      if ShiftState = [ssShift] then
      begin
        // the similar do for SHIFT shortcuts
      end
      else
        // etc.
    end;
  end
  else
    inherited;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  EventMask: LRESULT;
begin
  EventMask := SendMessage(RichEdit1.Handle, EM_GETEVENTMASK, 0, 0);
  SendMessage(RichEdit1.Handle, EM_SETEVENTMASK, 0, EventMask or ENM_KEYEVENTS);
end;

end.