Mount a folder outside casper

[Are Venes]

Is it possible to mount a folder that is outside the casper 
filesystem(but on the same partition)?

Ideally I want to do this during boot-time, in /etc/fstab.

If not, how could something similar be done? I want to boot the system, 
save some documents to a folder outside the casper-system, and then be 
able to put it in my other computer and view it there.
(other computer runs Windows so it has to be on the first partitions of 
the USB-drive)

Thanks for answers and help.