Most flights to Madagascar start in Paris, the capital of France. So besides your international flight from France to Madagascar, you usually need a feeder flight, which brings you from your home airport to Paris, Charles de Gaulle, and back again after your travel. While booking these flights, please always consider some hours between arrival and departure. Charles de Gaulle is the largest airport in Europe, and only the transfer from your airplane to the other can already take an hour. Additionally, little delays are not rare in long-distance flights.
Further more, please do not check your luggage through when traveling to Madagascar from your home airport. Experience shows that it is much safer to fetch your luggage in Paris and check it in for the long-distance flight by yourself. In Madagascar, noone will deliever your luggage to your residence place as it is common in Europe, UK and US!