If you want to make a phone call via your Mac without using VoIP then you need to hook it up with a phone line. Skype is VoIP so I am not sure why you consider it as not and why do you think you can use Skype for dialing with your Nokia and using your Nokia network.

On the other hand, using a VoIP service is the easiest way of calling from a computer and most of the time it's cheaper too. I've been using Onesuite for 2 or 3 years now and probably saved more than $300 versus using my mobile phone.