asterisk users - Mar 2007 - Add current caller to junk-callers-database

Hello,

I'm wondering how one might set up a feature to add (in real-time) the 
current CallerID information to a junk-callers database.

After answering a call from an outside line and determining that the 
call was from a telemarketer or the like, the user could dial an easy 
specific code (like ** or 77),  which would cause the call to be 
transferred to a specific extension within the Asterisk dialplan, where 
the CallerID info would be added to the database, a recorded message 
played to the caller, and then the call terminated.

When that CallerID phoned again, the call would be diverted to voicemail 
or whatever automatically (instead of ringing).

Another specific extension could be used to add/delete entries from the 
database if necessary.

Any suggestion on how to enable a feature code to do the initial transfer?

Thanks,
Alvin