Whisper Mute Feature

[ShawnDev]

In 3CX they have a whisper feature that allows an extension to listen and talk to another extension while they are on a call without the other end of the call hearing. But in this instance if the Whispered to extension wants to respond to the whisperer the outside leg of the call can also hear.

Could I program a button so that when the user presses a button his voice only goes to Whisperer and not the outside leg?

Thanks in advance.