Translating between languages is a tricky thing. There is no software that can do this accurately, you'll need to proofread the output. That's OK if you're going from French to English, but I'm assuming you can't read French and would therefore not be able to proofread an English to French translation.
Having said that, you could check a translation to a certain extent by then translating it back to English again, and checking whether the meaning is the same.
As for software suggestions, I have no idea 🙁