Using the web based conferencing software

I am able to dial in (phone call) to conference  using pin number.
But the problem is  sip client(voice conf) is also asking that same
pin number.

in dialplan
confname@profile+[pin]
or in profile
<param name="pin" value="pin_number">

How should I set my dial plan so that only phone dialing asks the pin
number.

Thanks