Hi,
Yes LREP can be used to replicate data and you can use USB drives.
Below are the steps:
1. In the source server install OSSV.
2. You will be able to snapvault data to the USB drive.
3. In your DC with netapp filer, connect the USB stick to any other server.
4. Use Lrep_writer in the server and snapvault command in the netapp filer for transferring the baseline.
5. Once completed, modify the snapvault to do incremental transfer from the source server to the Netapp filer.
Lrep tool is included in the OSSV package. You can also encrypt the data while copying to USB.
Hope it helps. If you need more details, let me know.