function LastPos(const SubStr, Str: string): Integer;
var
  Idx: Integer; // an index of SubStr in Str
begin
  Result := 0;
  Idx := StrUtils.PosEx(SubStr, Str);
  if Idx = 0 then
    Exit;
  while Idx > 0 do
  begin
    Result := Idx;
    Idx := StrUtils.PosEx(SubStr, Str, Idx + 1);
  end;
end;
//delphi/2322