How can I change the dial pad to stay active
 

Is there a way to edit the registry to make the dial pad stay activie after you answer a call? I have a security gate and when I get a call from the gate to let someone in, I need to key 9. On WM 6.1 when I answer the call the dial pad exits and I have to key "keypad" to get it back. Not a big deal except in trafic. Also happens when call any number that requires a pin number to proceed. If there is no hack to do this, is there a program to replace the dial pad?