Saroj,
20 MAC addresses is the maximum number that can be added to the WAP4410 and there is not a way to add more MAC addresses. I would look to the other devices on the network for this type of filtering. If the AP is connected to a router or switch you should be able to use their databases for the overflow. You may have to create two rules:
1. To allow only the list of specified MAC addresses
2. To deny ALL
Be sure to take a backup configuration of all devices before attempted and ACL changes. Hope this helps.
Blake Wright
Cisco SBSC Network Engineer