Use 7zip to Backup Network Files Onto Flash Drive

I want to use my USB Flash drive to backup network files.
It looks like 7zip Portable wants to backup my USB Flash Drive onto a some other media (local, network or otherwise).
Can I Use 7zip Portable to Backup Network Files Onto a USB Flash Drive? If not, can you suggest some other open-source product?

Active Backup Expert Pro
Full-featured backup tool creates automated zip- or cab-format backups of local and network files on hard disks, CD/DVD and other removable devices, local network or FTP site. Use Incremental or Differential mode to back up only new or changed files.
http://www.sharewareconnection.com/active-backup-expert-pro.htm