transit visa for France

We are considering adoption from the Ukraine. Although I am a US citizen and we live in the US, my husband is still a French citizen. We would like to leave our older son (he's almost 2 now) with his grandparents in France while we spend our time in the Ukraine. On the way home, I understand we will need a transit visa if we want to bring our new little one into France because she will still be a Ukrainian citizen. Has anyone had to get a transit visa, especially one for France? Can you tell me how it worked? Or anywhere I might find good information? Many thanks, Lori Beneytonloricalla@aol.com