Your UI setting file names are defined by your "short name" of your server that you put in your config file. So, every time you change that, new UI files will be created and you will have to set them up all over again. But once those settings are in place, as long as you don't change the short name again, your UI files won't change.
As a nice little trick;
1. Go to your EQ directory and find the 2 files associated with UI for a server name that you already have the UI setup exactly as you want it. They will be named something like name_servername.ini and UI_name_servernamel.ini
2. Make sure to find 2 that both have the same character and server name in them. Then copy and paste them to the directory you are already in. This will make files named "copy of name_servername.ini" and "copy of UI_name_servername.ini".
3. Make sure you have already logged out of the game, otherwise any changes you make now will just be overwritten when you do log out.
4. Now you want to find the exact files of the character that you want to have the good UI settings copied to. Normally this will be a new character that you haven't set the UI up on yet. Delete the 2 files related to that character. But make sure to take note of the names of the files.
5. Rename the "copy of" files to the same of the files you just deleted.
6. Log into the game and enjoy your easily setup customized UI
As an added note; if you already know the name of the characters you will be making before you make them, you can make multiple copies of the files and put the character name(s) that you will be making. This is great for people who like to try multiple servers and like to multibox. It can save alot of time.
I thought this was something everyone knew about, but I was talking to a friend and I mentioned it and they wished they had known about that years ago lol. Figured if they didn't know, then maybe this post can help out a few people here who don't. Of course, this post will probably be lost soon anyway lol.