does the call firewall app work for this?
http://www.freewarepocketpc.net/ppc-...wall-v1-4.html
there are other similar apps out there if you search. Some of them cost money, but might have more advanced features.
call firewall website says:
f. Black List Pattern - any no STARTING from the black list pattern list is rejected.
for eg. if you enter "123", so all nos STARTING from "123" will be rejected
this is a very nice option with which
you can block nos from any particular network,
country, city , area or whatever you can think of