Extract the subs, .idx and .sub of each cd, place them in the folder where you have the .avi(s), rename the subs with the exact name of the .avi, install vobsub where you want.
Open the movie and you'll see a green arrow near the pc clock, right click on the arrow and select subtitle's language.
You can grab vobsusb here:
http://www.free-codecs.com/download/vobsub.htm