This is (I hope) something really simple and obvious; how do I configure the MAC Filtering on an AP-700 access point to be a blacklist (banning access for the listed MACs) as it currently only appears to work as a whitelist. What am I missing?

Or do I even need to?
The AP is currently connected to a 2850 which already has a blacklist of its own configured with the same addresses that would need to be set up on the AP. Will that list be sufficient to block wireless access for those MACs through the AP?

The AP-700 is Rev. A hardware running Firmware v.1.08.
The router is a Vigor2850n running with Firmware v.3.6.2_232201

Probably worth mentioning that MAC address filtering is entirely ineffective as a method of security.