hey I'm interested as well!
not knowing anything of the system and the required C code....how hard do you think it is to pull out a reusable library from the "lot of C code" as you say it?
something vary basic as "ethernetWrite" and "ethernetRead"
I'm not a hardcore C coder (hardly a C coder at all

) but I'm a lot into building libraries, expecially for this ethernet connectivity.
do you think that it is possible to see an example of the "lot of C code" or at least the structure of it to better understand how to use the ENC28J60 chip?

I had a look at the datasheet and it does look a bit cumbersome but I think that from a coding point seeing an example can help in simplifying things...
let me know
I'm already in ether for ethernet arduino

b.