🚀 go-pugleaf

In Delphi 4.0, I'am trying to store in a stringlist an object responding
to an interface IReactToTimer. But the compiler give me an error
something like "incompatible type IReactoTimer, tobject"

I read that it was not possible to cast a interface to an object. I do
not need to cast my interface but just to store only objects responding
to specify interface. To get the maximum chances to have a clear code at
compile time I don't want to accept directly tObject instead of
IReactoTimer. The most error delphi found a compile time the less error
I will got a run-time. Problably the stringlist is not the way to use to
store my object, is there an other way to have same functionnality ? 

Initially in delphi 2.0 tTimerObject was heriting from a class
tReactToTimer and it was working fine. I've read that interfaces were
build exactly in so cases. 

The code:

Type
  IReactToTimer = interface(IUnknown)
    procedure TimerNotification;
  end;

Type
    tTimerObject = Class(TObject)
  private
    { Private declarations }
    RegisteredObj:tStringList;             
  public
    { public declarations }
    constructor Create;
    Destructor Destroy; override;
    Procedure RegisterToTimer(AObject:
IReactToTimer;TypeNotification:Integer);
    Procedure UnRegisterTimer(AObject: IReactToTimer);
    Procedure Event;
  end;

implementation

{ -------------------------------------------------------------------
                                                                Timer
  ------------------------------------------------------------------- }
constructor tTimerObject.Create;
begin
  Inherited Create;
  RegisteredObj:=tStringList.Create;
end;

Destructor tTimerObject.Destroy;
begin
  RegisteredObj.Free;
  inherited Destroy;
end;

Procedure tTimerObject.RegisterToTimer(AObject:
IReactToTimer;TypeNotification:Integer);
begin
  RegisteredObj.AddObject(IntToStr(TypeNotification),AObject);
end;

Procedure tTimerObject.UnRegisterTimer(AObject: IReactToTimer);
Var lIndex:Integer;
begin
  lIndex := RegisteredObj.IndexOfObject(AObject);
  If (lIndex <> -1) then RegisteredObj.Delete(lIndex);
end;

Procedure tTimerObject.Event;
Var i:Integer;
begin
  With RegisteredObj do
  begin
    For i:=0 to RegisteredObj.Count-1 do
    begin
      (Objects[I] as IReactToTimer).TimerNotification;
    end;
  end;
end;

(Send me directly a copy of the answer, i've got some problem with the
news reader) 

Kind regards
Eric.