From Chamonix to Italy

I haven't. I tried once but weather was not permitting the gondola to operate.

Are you talking about Rick's suggested gondola ride completely over the Mer de Glace into Coeurmayeur? That takes you into Italy and then bus to the train station in Aosta (I believe that's the closest train station) and then you're on your way to Rome!

No Switzerland involved.

But don't make travel plans that depend on the gondola(s) running the day you need it.

Jesi, You'll train from Paris to Geneva, then connect to Chamonix. At Chamonix you'll take the cable car to Aiguille du Midi. At Aiguille du midi you will catch the gondola over Mer de Glace (Sea of Ice) into Italy at Helbronner. It's a fantastic ride! From there you take the gondola down into the valley--I believe the village is Coeurmayeur. Take the bus to Aosta for the train to Rome. You do not need to go deep into Switzerland or back to Lyon. I will alert you that crossing the Mer de Glace to get into Italy that way can work only if you are travelling light. It's not the way to go if you're burdened with luggage. The gondola cars from Aiguille du Midi to Helbronner are small! They have room for only two people with a backpack each.

You don't say when you are going, but I would advise having a back up plan for getting into Italy. The gondola runs seasonally (it was closed the end of September 2008 when I was there) and also only can run when the weather is good. In 2001, I was there for 3 days and the gondola was open one afternoon. (September)

Thanks, everybody! That gives me a way better idea. I'm considering it, as my journey is in July (not by choice; it's just after a study abroad thing) but I am limited for time.
Jessi