You need to play with CSS and Partitions here. In layman terms
CSS :- Who can I call !!!
Partition :- Who can call me !!!
For Ex :- Phone A is in Part_A , Phone B is in Part_B and Phone C in Part_C. If you want Phone C should be able to call A and not B, here is what you would do.
In the CSS of Phone C you would add Part_A [so that C can call A] but not Part_B [so as to restrict calling to Phone B from Phone C].
In your scenario you can put ext 3333 in a partition which is not accessible by the calling number CSS [whether a phone CSS or Incoming CSS on gateway]
For further information on CSS and Partitions kindly check below link
http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-callmanager/22325-part-css-tn.html
HTH
Regards
Abhay
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Regards
Abhay Singh Reyal
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