Italy help at any time

I take it brian is no longer about well guys and girls am off on a tour in a van which includes running from swiss on a carnet and running down to palermo any info and advice would be welcome has anyone ever crossed at como into italy on a carnet if so where do you get it stamped ? never done sicily but looking forward to it im doing the shortest crossing to sicily how much is the crossing in a van thanks in advance>