If your not/can't use your ergos why wouldn't you just sell them then purchase the shifter that would work for your drive train? Why attempt to rip apart something good?

So your drive train is a Shimano RD and a Shimano 8s cassette?

How about these:
http://www.amazon.com/Shimano-SL-BS6.../dp/B000F5EFOC

8s shifter for $60. ready to go and everything and your Ergos should at least bring twice that. 9s is just a little more.

I understand wanting to use something you have but in the case of Campy shifters cobbling something together usually triples your budget and time to make it work.

I understand now where you were headed but a late era sets of Campy DT shifters sell for $100+, the typical 9s DT in good/new condition usually sell for $180+ . You can't use anything from Campy that has the 2 spring indexing with the ergo cams which is 99% of what you see as "affordable" DT Campy shifters, usually 7s. Shimanos at $60+ are a deal and you don't have to cobble anything together. And if you sell your ergos you would make money on the deal with Shimano shifters.