Niklas,
I've used a program called CRYPTOR for this type of application (although not with VFP. CRYPTOR basically works in between your application and your hard drive to encrypt the data as it is being written. I belive that this would be a possibile solution that is easy to implement.
Another solution (less elegent) would be to put a network workstation in
the safe (of course, you would need holes to handle the cables, etc). Write the data to the hard drive in the safe and you're all
set <g>.
Regards,
Michael