How 2 open .dat :(

Hi 4chan. Please help me open these darn .dat files.
They have an .xls (excel) file in them... but I don't know how to open this .dat file.

You can get the .dat files here: http://www.megaupload.com/?d=PHJBAT6L
or here: http://files-upload.com/247181/Language.rar.html
they're in a rar.



You're my only hope!

I simply want to translate all the korean text in the client from korean to english (I'm fluent in both languages) so that english speakers can also play this game. I have done some work translating NPC dialogs so far, but the .dats I don't know how to unpack and then repack (so that they work with the game)