Hi

This is quite easy really all you need to do is the following.

at the top of any script you like add a step to capture the calling number and store this in a variable. The blow this use an if statement to check the called number is the one you wish to block.

If (CallingNumner == "9012345678901")

if true just end the call if this does not evaluate leave the false alone and the script will continue.

Hope this helps

;)