Even if you had the editor it wouldn't help. The MX editors let you import from CCF files, but they don't let you export to anything nor view the Pronto Hex.

It might help to give the URL of the mxf file. A few of the experts know ways to get from an mxf file to Pronto Hex (including anyone who has both types of remote could just learn from one to another). I won't have time to help you that way, but maybe someone else who knows how will feel that generous.

Also, what is an rp8078? RCA is usually consistent about IR signals across a wide range of models of the same device type. Probably you can find and use a CCF file for a different model.