If your label maker has windows drivers and it appears in the list of printers like any other, then it's only a matter of making the correct PrintDocument object with the right size and number of pages. If it doesn't appear in the list of printers, then I'm out of ideas... We actually chose not to support those printers for our application which targets business tag/bar code/etc printing.
PS. There may be more to it, we're not yet to the part of creating those printing templates and we've put it on ice for the moment.