Anyone can play there, regardless of skill level, even if you don't have occasion to play there.
There's a riff in the second chorus of Hotel California that has a bend on fret 24. It's a pretty cool little riff. It's a good starting point if you just want to try using that fret sometime.
I don't know if anyone in Eagles actually had a 24 fret guitar. I think they used a pinch harmonic to hit that note? No idea. I don't know much about Eagles.
It may have been a pinch harmonic, it may have been a bit of feedback, but I don't think it was played at the 24th fret.
Just checked a few videos. Don Felder shows the lick starting at about 7:45 in this one.
Watching a couple live clips, he played it in the same spot - it definitely lacked the higher pitch I hear on the studio version. Steuart Smith in another clip played it in the same position but hammered on to a note way up in the 20s - it cuts away before you see the actual hammer. And I've seen Smith play it w/a pinch harmonic. It'd be a heck of a jump to get up to 24 in the lick the way Felder shows it and do it smoothly. Not impossible, but impressive.