There is a lot of interchangeability between the Campy Ergo levers of the same design family. It looks like you have the early 8-speed versions. There are many used ones that come avaiable on EBay as well as their parts sometimes. Also you'll sometimes find a "good for parts only" lever. Some shops will have these older levers in their used bins too.

But there was a version of the Campy lever that used a different shift lever action then what's shown in your link (and from what i referenced). Make sure you don't have this different version. If you don't then reapirs should be only an issue of getting an older lever/part and the labor to install. If you have the version (that has the up and down shift action linked together on one lever piece, both ends of the lever move with either shift direction) then your search will likely be less sucessful. If this is the case consider switching to the more independent shift action levers design.

if you posted a photo of the broken part some of us (well, maybe me) might have a used replacement in out stash. Andy.