It's actually trickier than you probably want to hear. If it's a USB printer, there's a *chance* you might be able to do it using Dave. If it's not USB, you're totally out of luck if you want to print directly to the printer from the Mac.
A good (although annoying) solution is to create a public folder on the Windows box with read/write access. You can then save your documents to that folder using samba (saving the files as PDF's minimizes font incompatibility issues, etc) and print from there.
It really might just be easier to buy a new printer for the Mac- that's what I did, as all I needed was decent inkjet printing and I could get a solid HP printer cheaper than I could get Dave.
Hope this helps.