Subtitles are a their own type of formatted text file. They can have several forms - that conform to subtitle entry. There are huge number of third party file managers to do this like Subtitle Pro etc.
In SCS product Vegaspro you can use a third-party plug-in like Vegasaur to export a subtitle file type.
BUT it it is likely that managing inside of Encore regardless will be an exercise in its own way - so the third-party tools will not only be necessary, but they will not be the end-game either.