I want to backup users but how?
 

I use RedHat9 and postfix mailserver.
I have a copy of my linux OS in another HDD. Ones happened that my linux system crushed down and I just changed the HDD, and after 5 minutes my linux system started to work again. I was happy until I noticed that the new users witch were created after the system had backuped (the whole copy of system).
So my question is:
Is it possible to backup only the newly created users not the whole system?
If yes, please tell me!

Thank you!

Copy their home directories and the old versions of shadow, passwd, group files?