[tshering]

The beolingus dictionaries have a format that is not supported by penelope. Therefore, if you want penelope to convert these two dictionaries to the Kobo format, you have first to convert them into something that penelope understands. A quick search with google didn't show any converters for beolingus. So maybe you have to do it yourself (or to have somebody do it for you). I think converting to xml might be the easiest way. If you want to make use of all the information included in these dictionaries (grammatical forms, synonyms, ...?) it might need some effort to achieve this. But even if you convert it in a way that makes use only of the main key words, the result might be a nice dictionary (compared with the original Kobo dictionaries).
Edit: You can see a sample xml file: penelope\test.xml.