Thought I'd have a look at how Celestia's cross-index code works and try adding a new cross-index to make sure I understood things properly. Chose HR because there aren't many HR designations already defined in Celestia's default files, and I had been recently working on implementing HR 8799's planetary system and kept forgetting the HIP/HD designations when it came to testing it in Celestia.
Here's a patch which incorporates an HR cross-index into Celestia. Apply the diff file and place the hrxindex.dat file in the data directory. Recompile and you will end up with a bunch of HR designations.