Hi redtop, that looks like a gorgeous hotel. Have you tried emailing them to ask about transport?When I looked at their site it looks like they organize tours and so on.( I'm sure they could organize a driver to collect you but it may cost more than if you organized it yourself)

You could call, there are so many English speaking tourists in that area that there is sure to be someone at the hotel who speaks English.

My husband and I were in Naples and the Amalfi coast for two weeks this past October and had a great time. The staff at all the hotels we stayed at spoke English.

The other thing you could do is grab a taxi outside the train station and have them take you to Positano. We took a cab from Naples to Sorrento and it cost 100 euros.
Someone else might have a suggestion of a car and driver service you could pre-book.

Are your flights cast in stone? Because it would be much easier to fly straight into Naples and then home from Rome rather than flying into Rome and then having to deal with getting the train to Naples etc while jet-lagged.
I saw your remarks on the other thread about the safety of the train station in Naples.I came into Naples by myself from Florence on the train and met my husband at our hotel in Naples.
The train itself was fantastic. I was very careful about my belongings once in the station as I had an interesting experience with a tag team of 3 thieves in the Florence station. But it was fine and I went straight out to the taxi rank which was all very safe and organized. Once we pulled away though I was pretty dumb-founded by the scene on the periphery of the station. OMG.
Glad I wasn't walking through that area with luggage etc!!