ImageEnVect.SelectObject(ObjectIndex or something);

procedure TForm1.SelectObjectFromID1Click(Sender: TObject);
var
  i: integer;
  hObj: integer;
  iID: integer;
begin
  hObj := -1;
  iID := StrToInt(InputBox('Get Object From ID', 'Enter An ID', '3'));
  for i := 0 to ImageEnVect1.ObjectsCount - 1 do
  begin
    hObj := ImageEnVect1.GetObjFromID(i);
    if ImageEnVect1.ObjID[hObj] = iID then
    begin
      ImageEnVect1.ObjPenColor[hObj] := clRed;
      break;
    end;
  end;
  if hObj = -1 then
    MessageDlg('Object With An ID of ' + IntToStr(iID) + ' was not found', mtWarning, [mbOK], 0);
end;

procedure TForm1.SelectObjectFromIndex1Click(Sender: TObject);
var
  i: integer;
  hObj: integer;
  iIndex: integer;
begin
  hObj := -1;
  iIndex := StrToInt(InputBox('Get Object From Index', 'Enter An Index', '1'));
  for i := 0 to ImageEnVect1.ObjectsCount - 1 do
  begin
    hObj := ImageEnVect1.GetObjFromIndex(i);
    if hObj = iIndex then
    begin
      ImageEnVect1.ObjPenColor[hObj] := clRed;
      break;
    end;
  end;
  if hObj = -1 then
    MessageDlg('Object With An Index of ' + IntToStr(iIndex) + ' was not found', mtWarning,
      [mbOK], 0);
end;

procedure TForm1.SelectObjectFromName1Click(Sender: TObject);
var
  i: integer;
  hObj: integer;
  iName: string;
begin
  hObj := -1;
  iName := InputBox('Get Object From Name', 'Enter An Name', 'Ellipse');
  for i := 0 to ImageEnVect1.ObjectsCount - 1 do
  begin
    hObj := ImageEnVect1.GetObjFromName(AnsiString(iName));
    if ImageEnVect1.ObjName[hObj] = AnsiString(iName) then
    begin
      ImageEnVect1.ObjPenColor[hObj] := clRed;
      break;
    end;
  end;
  if hObj = -1 then
    MessageDlg('Object With An Name of ' + iName + ' was not found', mtWarning, [mbOK],
      0);
end;