function StripHexPrefix(const HexStr: string): string;
begin
  if Pos('$', HexStr) = 1 then
    Result := Copy(HexStr, 2, Length(HexStr) - 1)
  else if Pos('0x', SysUtils.LowerCase(HexStr)) = 1 then
    Result := Copy(HexStr, 3, Length(HexStr) - 2)
  else
    Result := HexStr;
end;
//delphi/2255