I did the COBOL lexer a while back, and then neglected the bitbucket account and now I'm bwtiffin instead of btiffin. Here is a Unicon lexer, which includes a lexer for the more famous Icon language and one for the VM sources called ucode. Conflicts dictate that Unicon (the newer still in development fork) gets .icn and Icon (project was marked complete quite a few years ago, but still has a loyal fan base) gets .icon.
I did all the work inside Bitbucket online, and failed to notice the current example.u file when I did the Add File. So, there is a borked commit over the older .u, then corrected. ucode also reacts to .u1 and .u2 so I just added a new .u1 file.
If there are any issues, drop a note here or feel free to send me an email; bwtiffin at the google mail dot commercial.