Looking to Block a number, a head-hunter service keeps calling my employees!

I have one routing table setup to route the calls from my PRI to the desired applications. The "Pattern" is the last 4 digits of the DID and the "Description" the the endire DID. Ring-In Type is "Single" and then Ring-In Destinatio is the application.
So how would I apply this to block a caller ID number? Do i put the entire number in the "pattern" (area code and 7 digits withouth () or -)?

Just lookin for a little help.

Thanks, as always.
Andy