procedure FindAndReplace(P: Variant; SearchStr, ReplaceStr: string);
var
  i, j: Integer;
  ppSlide, ppShape: Variant;
begin
  for i := 1 to P.Slides.Count do
  begin
    ppSlide := P.Slides.Item(i);
    for j := 1 to ppSlide.Shapes.Count do
    begin
      ppShape := ppSlide.Shapes.Item(j);
      s := ppShape.TextFrame.TextRange.Text;
      s := StringReplace(s, SearchStr, ReplaceStr, [rfReplaceAll]);
      ppShape.TextFrame.TextRange.Text := s;
    end;
  end;
end;
procedure TForm2.SpeedButton2Click(Sender: TObject);
 begin
    try
     ppApp := CreateOleObject('PowerPoint.Application');
     except
     ShowMessage('Error...');
     Exit;
    end;

    ppPres := ppApp.Presentations.Open(ExtractFilePath(Application.ExeName)+'sld.pptx',False, False, True);
    ppApp.ActivePresentation.SaveAs(getcurrentdir+'sl01111d.pptx');

// вызов: 
FindAndReplace(ppPres, '222', '111')