ABR11.5 - within Parallels VM, is backup directly to \\.psf\share possible?

I have Parallels Desktop for Mac. Inside my Windows 7 VM it creates a special share for access to folders on the host. I would like to backup directly to the share "\\psf\Data", which is the volume on the Mac host which contains my backups, etc. ABR11.5 does not see "\\psf\". The share is mapped to Z: already, but ABR11.5 cannot see mapped drives (I suppose because it's running as a service). "net use" reports that the share name is "\\psf\Data\", but I have also tried specifying the destination as: "\\.psf\Data\", "\\localhost\z$\". Each time I get (something similar to) "The network name cannot be found" and "Failed to retrieve information about file '\\psf\Data'". I've included the detailed error message below. So, I'm looking for a workaround that will allow me to back up the VM directly to the Mac...

note: I know about but am not satisfied with Parallels' snapshots+TimeMachine solution for backup, because I need to be able to occasionally compress the virtual disk, which you cannot do without deleting all snapshots.

I could run Samba or ftpd on the mac side, but that seems pretty over-the-top.

Could I add a pre-backup command "net use x: \\psf\Data", so that the service understands the share, then manually edit the backup plan's destination to be x:\path\to\backups? Anyone have another idea?

BTW, the most similar previous posting I've found here or via Google is http://forum.acronis.com/forum/4566

detailed error message:
"
Code: 9,568,519(0x00920107)
LineInfo: 0x9A79F20828BC7F9;

Module: disk_bundle_vs_32266
Message: Failed to retrieve information about file '\\psf\Data'.

Code: 9,568,519(0x00920107)
LineInfo: 0x4D7F75FCDE07D65F;

Module: mms_vs_32266
Message: Failed to retrieve information about file '\\psf\Data'.

Code: 262,165(0x00040015)
LineInfo: 0xBD01591C540A142E;

Module: disk_bundle_vs_32266
Message: Network disconnected.

Code: 65,520(0x0000FFF0)
LineInfo: 0xBD28FDBD64EDB8E0;

Module: disk_bundle_vs_32266
Message: The network name cannot be found
"