Hide dial number

[hwtsai]

I am setting up PIN before making call, and it seems to work so far. But the problem is, Yealink T20 would not hide the PIN no as I entered. For example I would like to call 12345678 and my pin is 9999.

First I would dial 12345678 as usual, and Yealink would reply with "Please enter your password/authorization bla bla bla" and then I dial/enter #9999. It works. But this "#9999" shows on screen which is easily can be seen by others. How do I hide this 9999 and replace it with **** ?

Thx for any help.
Tsai