Unlisted number and Star Codes

If it's unlisted from the phone company, there is no way for you to do what you're asking. If you have digital service and you have blocked the outgoing caller id than yes you can do it. The difference is did you do it or the phone company. 

Thank you!!!

 you have U-verse you can block quite a few.  Also you can use Nomorobo with U-verse there is a link on the right that explains it. If you have POTS there's a lot of devices out there that will block 100's of calls, if on the devices list it put's out a reorder tone to the caller.

That has nothing to do with the topic.