As I remember it's not haali but internal MPC splitter that is needed. The engine that is integrated to MP already supports such subtitles, but there is no splitter that delivers them.
I can't test this right now but I'm 100% sure that I tested this last week and I where able to show the subs of a newly ripped blu-ray .m2ts file in mpc-hc.
By using 1.1 Beta + SVN
Comma separated list and supports relative paths also. Can't be that hard?