There is a rename script to do that but I am not sure if it will work inside archives. It may be possible to make it work (using some things which were added to Opus scripting after the script was written; the script is quite old), but I suspect the script would need to be changed at least a bit.
If you're renaming hundreds of files within archives, are you not finding it quite slow? I would expect it to be, as we have not optimised mass-renaming to work within archives. (It should work, but it will rename one file at a time, and isn't a common use-case that we've made explicit optimisations for, at least yet.) If you're running into other restrictions with renaming inside archives then I'd definitely consider extracting them, doing the rename(s), then re-creating the archives. It will likely end up being faster that way as well as giving you more flexibility.
Edit: This is the script, and it definitely won't work with archives at the moment as it uses native VBScript functions to check if the files already exist, and they don't know about archives. Re-writing it to use Opus functions (FSUtil.Exists) may make it work, but I would not expect it to be very fast inside an archive.