I am not Herwig, and I am guessing at this (I haven't actually done it), but try:
Install the printer driver on the guest machine. After it is successfully installed, you will have a printer icon. Open the printer properties, and go to the Output Port tab. You need to install a new SMB port for the printer, and select it, then open the port properties. There, you will see the logon information that you need to fill in.
Whether it works, or not, I don't know. The same procedure seems to work okay when using a CUPS printer port to redirect output to another machine, with CUPS installed.