What IP is your client? That nfs- export is visible to subnet 10.0.0 only, with a 24 bit subnetmask, so a router will be needed between server and allowed clients. Unfortunately, I don't have any experience with nfs across routers.
Also having read this again, I doubt if you'll be able to do this easilly without changes to the networking as well - there may even be a need to have static routes set up by the network team if you have one.