How to use internal "Lync" dial function on segment dial number

Hi,

sind NAV2009 we have the new Lync/Dial icon besides phone number if we set the ExtendedProprty to Phone Number.
This works great in our environment and dials directly via out swyx IP phones.
When I use the the dial phone number wizard the system tries to dial by codeunit 5053 TAPIManagement.
Unfortunatly in these situations the windows internal dialer.exe pops up and does not dial the number.

Does anybody know the difference of both "ways" and how to use the lync dial functionality that works from contact card?

Thanks in advance!