var

  fname: string;

  WordAppl, WordDoc: OleVariant;

begin

  with TOpenDialog.Create(nil) do

  try

    Filter := 'word documents (*.doc)|*.doc';

    if not Execute then Exit;

    fname := FileName;

  finally

    Free;

  end;

  WordAppl := CreateOleObject('Word.Application');

  try

    WordDoc := WordAppl.Documents.Open(fname);

    fname := ExtractFilePath(fname) + 'test.htm';

    WordDoc.SaveAs(FileName := fname, FileFormat := wdFormatHTML);

  finally

    WordAppl.Quit;

  end;

end;