Its really not much Work..
Create a new file such as locale.lua, insert there your Texts, maybe sth like
Code:
bla[1] Eng
bla[2] Ger
bla[3] Sth other stuff
bla2[1] ... going on ;)
and load it in the questlib.lua with dofile.
And save the player's Language in some Mainflag... So create an empty quest named questlang and use everywhere this:
pc.setqf('questlang','lang',1) (Eng)
pc.getqf(('questlang','lang')
I would do it a "little" bit different from this idea (such as loading other locales and using metatables, but..

) but i think this option is okay for you
i have to go now, in some hours i can write you a system for this - but i'm going to publish it, so everyone can use it.. many people could need this stuff
Greets, Mijago