reg expression help

[eluser]new_igniter[/eluser]
Hello,
can a reg expression guru help me out here?

I have a Google Maps address:
(47.718691, -122.28464)

How do I
a) get rid of the parentheses on the left
b) split the values at the comma into 2 variables
c) get rid of the closing parentheses on the right

so I end up with,
$a = 47.718691
$b = -122.28464

Thanks!!!