said by hubrisnxs:
you can only do that in a windows server environment where you set group policy's etc. The block 53 won't stop them from changing their dns setting on their PC, but it will stop them from using other's
That is not entirely true, while that is one way to do it you can also do it using most enterprise grade firewalls however the actiontec does not really fall into that category.
To the OP: The sad part is, part of the functionally to do what you want is available under the advanced filters section but not the part that lets you re-direct requests to a specific address, it only lets you block them.