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 ?  
) T+ e/ _; D& F: c* P7 p5.39.217.769 Z" |0 B7 n7 O: h$ C- h, v7 b
thanks in advance.