Hi, and welcome to the Community! 
I’m with you—Spanish would be awesome. Unfortunately, we don’t have any new language versions on the horizon at the moment.
If you’ve got a Spanish dictionary as a .txl file, you can use that and still work with most of Papyrus Author’s features!
Here’s a topic on dictionaries and how to add one: Spell Check in other languages please
I hope you’ll find a way to make it work, and have fun! 
