If your need is to simply determine the digits in PI and not use this extended precision number in any calculations, then all you need is an algorithm. Sorry that I can't suggest one, but a Google search should turn up several sources - or maybe someone here could recommend one.

To clarify: the extended precision digits could be stored in an array of integers or as ASCII characters in a string. Obviously, if stored this way you would not be able to use the value in any calculations.