I wasn't sure if you meant software that can do this, but I think you need the human touch, the efforts of people who are interested in the language. The people at this discussion board would probably like to help:
They are forever translating and picking apart the language in a most impressive way. I think if you post your question there (no registration necessary), it will become a thread.
French being my mother tongue, I can give you a hand on that on a courtesy basis.
Having said that, the translation I would give you would not be to "Cajun French", but to standard French which is what is utilized for most Acadian and French Canadian songs (including Zachary Richard). I might be out to lunch, but I'm not sure if there's such a thing as translating in "Cajun French". I suppose you could substitute some words from the standard French to reflect some words that are unique to Cajun culture (i.e. crocodile for cocodrie) to give it a Cajun touch. I don't know how else.