Carlos
The short answer is you can't as far as i know. You need to do NAT to able to do this and i don't think the Nexus switches support NAT.
You need a device that can NAT both address ranges. If prod is always the one that initiates the connection then you need static NAT translations for the test machines and you can dynamicaly NAT prod addresses as they go into the test env.
But if both prod and test can initiate connections then you need to have static NAT translations for both sides.
We used a pix firewall for this when we connected our prod and test environments. A firewall is a good choice because you can make the test enviornment the outside interface where all traffic is denied by default. You do not want test affecting prod.
Jon
