Hello wsnuist,
mozart2camx (distributed by the developers and maintainers of the CAMx model) is not a tool that is supported by the CMAS forum team.
That said, there may be some users of this forum who have tried developing BCON and ICON for CMAQ using CAM-Chem input fields, and may have adapted mozart2camx or other custom tools like this one to accomplish this task. If so, they might be able to provide some guidance to you.
The discussion in this previous thread (related to CAMS, not CAM-Chem) may provide some general guidance. In particular, Table 1 in this paper linked by @lizadams in post #6 of that thread might be a good starting point to modify existing species mapping files to meet your needs.