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 ?  
' o( k' I4 x9 S; |8 T  {5.39.217.765.39.217.76% G9 Z9 K5 W4 z. o6 t3 {
thanks in advance.