wildcard zone

[etr]

Hi to all,

i would like to implement a dns service that works in this way:

If a domain requested exists my server will answer with the correct IP but 
if a domain does not exist, i would like to answer with a "standard IP".
Example:

Request:   google.com  Answer: 64.233.167.99
Request:   adedaf.com  Answer: 1.1.1.1
Request    bcbcdf.com Answer: 1.1.1.1

I've tried to do this adding a "." zone to the named.conf, the standard 
answer for unextisting domains works succesfully but, of course, i can't 
solve any domain for wich i'm not authoritative because i do not know how to 
add the standard zone for the root ns.

Thanks in advance for any hint.

Ettore

P.S.  I think that what i want is similar to what OpenDNS offers in fact, 
when you type an incorrect domain, you a redirected to a search page ...