We found a utility called NXtract which seemed to work fine, unfortunately the free version only allows up to 5000 rows, and we didn't have time to buy the full version (it would involve lots of admin!).
We have managed to re-install our version of Oracle and are using the imp function. Oracle Lite is available as a free download for anyone who doesn't have access to a full version but I have no idea how well it would work in this situation.