It's my understanding that Dial Phone is no longer compatible with Mac systems, but I could be wrong. It can be used with FileMaker Go on an Iphone interestingly enough, but that's not what you are looking for here.
If you haven't already done so, you might research filemaker plug ins to see if a third party developer has come up with something that will work. I don't know of any such item, but you never know until you search...
One of the companies we are working with found a program - Dialectic. Works pretty slick. Can be used in writing scripts or basically right click on anything that is a phone number and select dial. We will be using to dial our hard and soft phones. Very cool stuff!