...Sounds to me like he's trying to convert short RC5 codes for use with another program that can import standard Pronto learned hex.

If he hadn't mentioned that the file was for a Marantz remote, for all we know the code could also have been a database code, and even still I suppose that he could have 7000 or 8000 formats.

So: if it's a 5000 series code John's provided your answer, otherwise please post a sample of the code and let us know exactly what it's for.