I'm pretty sure you are out of luck.  The IRClone software & hardware was developed around 12 years ago.  The software has long since been orphaned.

Many of us bought the IRClone software/hardware package and loved it for our MX-500's.  However, the majority of MX-500 owner's moved on to the newer HTM remotes that came with their own programming software. So interest in IRClone dropped to where it was not worth it to South Shore Technologies time to keep it updated.

I think your best bet may be to create a Windows XP VM on your computer and use that to program your remote using your existing software.

Mike