You'd need to "explode" the .lit and .prc files and then create a script or even a macro that would turn the dictionary entries into a tabfile format, i.e.
Code:
entry1 definition
entry2 definition
entry3 definition
(Between entry1 and definition there's a tab character, the one to the left of the letter Q on your keyboard.)
And then use the stardict-editor to convert the tabfile to stardict format.