French number to text conversion has now been implemented.
Numbers to Text is used in Thank you letters, using the <WordAmount> field (Built-in letters) and <TextAmount> field (Word Merges), as well as in Printing checks using <tTextAmount>.
Click Program Setup > Options > Letters/Receipts tab > Word Amount field, and choose French from the Drop-down.
Please note that this feature is in beta testing at this phase. If you are going to use this feature, please pay closer attention...