Travel from Benin to Niger through W National Park


I'm going to spend some time in West Africa in May, and I'm considering travelling from Cotonou in Benin up to Kandi, and then visit the W National Park. It would then be convienient to fly back to Stockholm from Niamey in Niger. My question, then, is whether it is possible to cross the border into Niger through the W National Park, i.e. can I come from Kandi in Benin, and get to Niamey in Niger through the W National Park?