Help with own RBL

[Pedro David Marco]

Not exactly a SA question but...
i am planning to run my own RBL with a nameserver, that when queried for an IP 
that is not in its database, does some calculations with that IP and replies 
accordingly (caching the results)...
Please, does anyone know of any nameserver that can do that? To my knowledge 
RBLDNSD cannot do it...
Thanks in advance!
-------PedroD