The problem is that Shimano and Campy cassettes are incompatible in 2 ways: 1) Campagnolo cassettes will not fit on Shimano-spline freehub bodies; and 2) the cogs on a Camp. cassette are spaced differently that Shimano cassettes. One way to use a Shimano compatible wheel with Campy shifters/derailleurs is to fit Shimano-splined cogs with Campy spacing on the freehub. A few years ago Ambrosio and Miche (and I want to say American Classic) would sell you a cassette just like that. I have one on a set of tubulars that I wanted to use with a Centaur/Chorus equipped bike. Unfortunately I have not seen those in a long time. The other way is to make one yourself, as suggested above.