I've come to a point where I need to join the fellowship and got to the passcode part of the game for the second time with Batlin. Everytime I get to the part of the dialogue where Batlin starts the first question of the passcode stuff, the screen glitches out and it kicks me out of the game. I'm running it on Dos Box from GOG. I know that I would be suggested to just play it from Exult, but I would much rather not do that since I've dedicated a lot of time to get to the point I'm at. Is there any patches or ways to get pass this part?

"Glitches out" how? Does the game itself crash (rare but known to happen) or does dosbox CTD?

Assuming a reinstall doesn't fix it, you can always just skip talking to Batlin ever again. The only thing you miss is all the Fellowship heads giving you the run-around on E&A's whereabouts.

It's possible to remove the copy protection.

Instructions:
1. Go to this link: http://patchery.net/patchery/patch.html?id=1000031
2. Open the location of the USECODE file in Ultima VII - default is C:\GOG Games\Ultima VII - Complete\ULTIMA7\STATIC
3. Drag the USECODE file into the drag-n-drop area on the webpage, then wait until it finishes scanning the file
4. When the page reports "SHA-3 match of original file", click the "Download patched file" button. This isn't a real download - the file is modified in memory by the page's javascript and the file download is sourced from your own PC's memory.
5. Rename the old USECODE file (to something like USECODE.backup) and replace it with the downloaded file
6. Run Ultima VII again and the copy protection checks should be bypassed the next time you reach that area

Well, I won't suggest you take it to Exult, then. But do know that the game is much more pleasant and easier on the eyes if you play through it. Not only can you have a higher resolution than the original and not be entirely zoomed in like you're playing on 320x200 -- meaning, it's scaled, to a varying degree of your choosing -- but, most importantly to my optical welfare, it has a scrolling smoothing feature, sparing your eyes from original experience's jerky screen scrolling, which immediately put me off. I wouldn't have played the game if I had to endure that, let me tell you.

I think, even for more tolerant-eyed old players of this game -- which I am not, playing it for the first time, first dip into the series -- they're bound to appreciate the efforts gone into this work. Hell, old players are who made it.

The main reason you need to join the Fellowship is to get to a certain part of the world. I don't want to give too much away, but you'll really only need to be in the Fellowship to get past a gate. If you get the magic carpet, you can simply fly over the gate to get to that location. (It's what i call a "soft" cheat. It's not really a cheat because the carpet is found in the game without cheats of any kind if you look hard enough). Other than that, Fellowship membership only gives you a few dialogue options/interesting responses (including one potentially good companion character who will attack you if you are in the Fellowship). If that's what's preventing you from going further, you can skip the fellowship membership. It really doesn't do that much.
Good luck!