There's really no major difference between a 10-speed triple Campy FD and an 8-speed one. If you're having trouble with how the old one you have works, go through the installation procedure carefully to make sure it is installed and set up correct for your new setup. There's also a cable tension aspect to the adjustment - get that right, too.
You might also compare the full cable pull range on the new shifter to that of the old shifter, just to make sure the new shifter is capable of handling a triple.