MediaInfo.exe "--Output=Text;%ID%: %Format%$if(%Language/String%, SUBTiTLE: .............. %Language/String%)\r\n" File.mkv
Output:
5: UTF-8 6: VobSub SUBTiTLE: .............. French 7: VobSub SUBTiTLE: .............. English 8: VobSub SUBTiTLE: .............. French
Jérôme, developer of MediaInfo