Sorry Vamp, I got a little bored earlier this week and decided to have a go at this.
The program can be found at the following link along with the source:
 New version. See post further down in thread for details:
Old version as discussed in this post:
This is a fairly early build with a handful of hours sunk into it. It handles most conversions quite well, but there are sure to be bugs. I only added minimal error-checking as I went along and the rest will have to wait until I have more time. If you encounter a bug, I've provided an e-mail address for bug reports in the read me.
What it does: Converts from any known format to any known format, including AR MAX. It cannot do CBv7+ or GSv5 (unless you strip off the extra lines that are prepended to GSv5 codes). Due to the vast difference between the MAX and other devices, very complex codes or obscure MAX code types may not convert exactly as they should. Check the readme in the zip file for what is and isn't handled and what potential errors exist.
As this is open source, feel free to use all or part of the included source in your own programs.
Thanks to Parasyte, Misfired for large portions of the encryption code and to Hellion for helping decipher the MAX commands.