Also, while I'm on a roll, you might look at a package that my Stats professor mentioned- SPSS.

At their web site http://www.spss.com/software/spss/devpg.htm, they have an area that states the following "Other resources include the Input/Output DLL (Dynamic Linked Library) to read and write SPSS data files."

I have no idea of its cost, but it is a well-respected package in the statistics arena.