If your Server is hosted on a CentOS Basis, why don’t you just mount your NAS Share to the folder where UrBackup writes your backups to?
For example: mount -t cifs //NAS/Documents /mnt/UrBackups
(Thats for samba shares, but depending on your Network Performance you might want to choose a Protocol with less overhead.)
i guess thats the easiest and fastet way 