Here is our recommendation.
As mentioned before, computer code should not be transcribed in Nemeth. But since your client insists, it would be better to use the old Computer Braille Code for the computer text. This would be an interesting mix of UEB, Nemeth, and CBC, and is not standard practice, but we feel it would be better than trying to wrestle Nemeth Code within the computer language. You would precede and follow the computer notation with the "non-UEB" code switch indicators. See Section 14 of the Rules of Unified English Braille.
IF you continue to transcribe the computer notation in Nemeth, the number following the percent symbol needs to be identified as a numeral, so a numeric indicator should be inserted.
Let me know if further problems arise.
- Lindy Walton