Hi adelatorre,
You are right, in that page, there is not much explanation.
You can only see the drawing in the "Overview" tab. This is the "SHARED STORAGE" option of the VCB.
Another option of the VCB is local DATA STORE to LOCAL FILESYSTEM.
If you have a LOCAL DATASTORE and enough free space for your backups in other filesystem (say /home/MyBackups), you can use "vcbMounter" without a VCB PROXY.
Connect directly your ESX Server host,
Edit /etc/vmware/backuptools.conf (according to latest VM Backup guide : http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_vm_backup.pdf)
And issua a command like this :
vcbMounter -a name:YOUR_VM_NAME -r /home/MyBackups
See alo my other resolution : http://communities.vmware.com/message/855099#855099
Good luck.