I'm also guessing, that if you were 'given' the remote codes, you were simply passed on the hex value for the remote code, not the full hex information necessary to put into a remote. I've never quite figured out how to get this code to work with anything that I've used and have always looked for the full Pronto style hex code which is far easier to get into the remotes that I typically work with.
Many companies simply are way to proprietary with their codes and setup and don't properly get them out to the most popular websites for people to use freely. This is generally why I recommend against products of this nature. How good is the product really when the manufacturer can't get you the proper codes, doesn't get the codes to reputable websites or universal remote manufacturers, and doesn't ship the product with a remote?
I would call Myriad up and have them ship one of their remotes to both Harmony and Universal Remote Control so the remotes can be learned and put into their respective databases.