Flagging for external subtitle at dynamic list

At dynamic list in Movie Library, is there any way to check the external subtitle file (srt file)?

I found this condition but it looks for internal subtitle (as far as I know) check not external subtitle.

<visible>IsEmpty(Window.Property(movie.SubtitleLanguage.1)) | !IsEmpty(Window.Property(movie.SubtitleLanguage.2))</visible>

Also, found another condition but it only valid when it playing video.

<visible>VideoPlayer.HasSubtitles</visible>