Hmm not sure I fully understand. I currently have 1 machine running cudaminer which doesn't seem to have a -addnode option.
Could you elaborate a bit on which program has this option? I assume this might be a different client that connects to a local server by specifying -addnode <local server> in its config somewhere. I imagine the setup to look like
<client> connects to --> <local server> connects --> pool on internet
Correct?
Oh. I thought you wanted to share blockchain data for Bitcoin clients, not miners. Supporting miners this way would be a little tougher since you basically have to create your own pool. If the pool you're mining on supports getwork (usually on port 8332 if it's there, though a lot of them've dropped support since stratum's far superior), you can download, configure, and run the stratum proxy pool. cgminer, cudaminer and the like don't natively support acting as a server over a network (AFAIK).
That's a goofy solution, though. There's probably an easier way. There's a list of pool software @
https://en.bitcoin.it/wiki/Software#Mining_Pool_Servers_.28backend.29 I'd guess you'll run into problems with the firewall, though.