Any "External Identifier" is just an "alias". I had such a table for my compounds. The compounds could be purchased or made in-house or both. There were also different IDs depending on the phase of the project. () If it looked like the compound *might go to clinical trials, it would get a new name for FDA, News outlets, other pharmaceuticals, etc.

(*) DO NOT let them name/ID compounds on their own!! Do whatever it takes to ensure uniqueness of those IDs. Humans LOVE to guess "the next number".. and usually get it wrong. This becomes a "business process" problem.

I believe there is a huge bioinformatics conference. I believe, in the fall in Boston. Get your company to send you. There is also a StackExchange for Bio-Informatics.