请问怎样用subtitile的file (sub) ??

alantct

i hv a movie file, Lelio.Po.Po.2010.DVDRip.XviD.ONiE and another two files (seprate) is the sub  & idx file. may i know how to use or combine the video file so that i can watch it with subtitle ?  
4 e0 d1 R6 g7 c: k+ g& P* N% W& d公仔箱論壇2 q& ?& f) i% |4 i) x# T
thanks in advance.