Is there any way to only add some characters from an addon character pack?

[Yatagarasu]

There are multiple addons where I'm only interested in one or two characters and have no idea who the others are

 

[scopica]

If people are merciful enough, they will give Individual characters in the form of a zip file.

 

[Jammin']

...Just don't use the others?
As scopica said, some mods have a ZIP file or something similar that contains the characters but separated.
Without the latter, unless you want to mess with the mod itself, there's no way to load individual characters from a character pack.