Currently no, Subtitles in mkv are new since the latest release. It has been requested for a while and the quickest solution for subtitles was to add INITIAL support through hardcoding them. Note the word INITIAL. This is only an interim solution, the selectable subtitles are on the to-do list but the current method was the quickest solution to add support. Selectable subs will get added in a future version, its just not possible right now.
Which format can I use to read with "Western Digital Live Center" ?I can't say, think multi-audio is supported i just cant say for sure. I don't make mkv's. The only way to know for sure is to try
It's little bit strange, around the web there are million of MKV with several audio track and several subtitles. Which software is used to do this ?