procedure TForm1.Button1Click(Sender: TObject);

var
  Stream1, Stream2: TFileStream;
begin
  Stream1 := TFileStream.Create('c:file4', fmCreate or fmShareExclusive);
  try
    { first file }
    Stream2 := TFileStream.Create('c:file1', fmOpenRead or fmShareDenyNone);
    try
      Stream1.CopyFrom(Stream2, Stream2.Size);
    finally
      Stream2.Free;
    end;
    { next file }
    Stream2 := TFileStream.Create('c:file2', fmOpenRead or fmShareDenyNone);
    try
      Stream1.CopyFrom(Stream2, Stream2.Size);
    finally
      Stream2.Free;
    end;
    { and so on }
  finally
    Stream1.Free;
  end;
end;

function AppendFiles(Files: TStrings; const DestFile: string): integer;
var
  srcFS, destFS: TFileStream;

  i: integer;
  F: string;
begin
  result := 0;
  if (Files.Count > 0) and (DestFile <> '') then
  begin
    destFS := TFileStream.Create(DestFile, fmCreate or fmShareExclusive);
    try
      i := 0;
      while i < Files.Count do
      begin
        F := Files(i);
        Inc(i);
        if (CompareText(F, DestFile) <> 0) and (F <> '') then
        begin
          srcFS := TFileStream.Create(F, fmOpenRead or fmShareDenyWrite)