Just an idea that may suit your needs. If you list all your own songs under a language that you don't use for anything else or even a genre, you can do this from the edit screen. Then in your show use the search box highlight
just the language tab, then enter your chosen language in the search bar, it should list all those songs.
I have probably got some where near 800 songs marked as Spanish and it will bring all of those up in about 3 seconds.
Roy