I have not done this, but I believe it's possible. Assume you figure out a way to convert from WAV to FLAC Here are some pointers and thoughts on how to read and write the OLIVE external disks:
1. The Olive runs a version of LINUX. Windows cannot read LINUX disk drives natively.
2. There are different versions of disk formats used by different flavors of LINUX. I would suggest a call or email to Olive (they usually take a week or so to answer, so be patient) to ask what disk format they use and what flavor or LINUX they run.
3. Once you know the disk format, just google a utility to allow you to read it from within Windows. Here are some examples (that may or may not be for the format actually used by the Olive; they would probably work, actually):
http://www.fs-driver.org/,
http://www.chrysocome.net/explore2fs.
There may be another option. If you have a network, the Olive exposes an "IMPORT" directory over the network. You can copy files into that directory and then import them on the Olive. I'm not sure the format accepted in that directory (it may be .WAV, actually -- whatever the "native" format of the CD is). The Olive might do the FLAC conversion on those imported files (or it might only allow cataloging them, I'm not positive). Again, an email to Olive is the best way to find out more about this (or perhaps others can fill us in).
Cordially,
Eric
p.s. Let us know what you discover.