[NumLock]

Код:

var
  registry: TRegistry;
begin
  registry:=TRegistry.Create;
  try
    registry.RootKey:=HKEY_CLASSES_ROOT;
    registry.OpenKey('\*\shell\Rnote\', True);
    registry.WriteString('', 'Открыть в Rnote');
    registry.OpenKey('\*\shell\Rnote\command', True);
    registry.WriteString('', Application.ExeName+' "%1"');
  finally
    registry.Free;
  end;
end;