TIdFTP na d directories beginning with "-"-sign

Hi!

I have a directory on my FTP that is called "-filer" (with a "-"- sign in
front of the directory name.

FTP1.List(s, '-myfiles\*', true);

This should list all the directories in the "-files" directory, but lists
the directories in the same dir as "-files".
If I use this list-command on a directory with no "-" sign in front of the
name, it works as it should.
Is this a Indy bug or is it bad practise to have "-" sign in front of a
directory-name?

This is my code (with hardcoded directory "-files")

var
  s: tstringlist;
  listitem: Tlistitem;
  x: integer;
begin
  s := tstringlist.create;
  FTP1.List(s, '-files\*', true);

 for x := 0 to s.Count - 1 do begin
    Animated1.Refresh;
    if copy(s[x], 1, 1) = 'd' then begin
      listitem := Transferlist.Items.add;
      listitem.caption := copy(s[x], 60, 255);
    end;
  end;

s.free;
end;