The instructions for enabling access to a Linux host's printer
from a Windows VirtualBox client goes like this:
1. Install your printer driver. Get your printer working.
2. Add your printer to CUPS at http://localhost:631/admin
If CUPS is not installed in your computer, go to the official CUPS website to download it.
You may also want to read the Ubuntu Official Documentation here.
3. Set your virtual machine's Network to Bridged Adapter (eth0) in Settings and connect the cable (Advanced menu).
4. Start your VirtualBox machine.
5. Enter "ifconfig" at a terminal prompt to list your current network settings
and copy down your host's (eth0) address. You can also access this address using Network Tools.
1. Add a new Network printer in "Printers and Faxes" from the Control Panel
2. Enter the URL address of your host's printer.
For example: http://192.168.0.2:631/printers/Your_printer's_name
You need the :631 after your host's address as this is the port
that CUPS listens to. Your_printer's_name is the name of the printer you added to CUPS.
If no connection is made, check your firewall settings.
If you want a Linux VirtualBox client to access a Window's host's printer, you're going the wrong direction!