I'm trying to multiply together a set of numbers.

However, the programs I have tried (Excel, R, FreeMat) do not allow numbers above around 300 digits. This limits me to sets of a few hundred numbers at most.

What program can I use that isn't limited by the number of digits? And what size numbers can I realistically manipulate on a (high spec) home PC?

I'm not a programmer, however I can learn if this is the only way around it!