This one is tough. Windows is designed to obscure specifics about printers in favor of a common printing model. Windows expects the user to select the type of the printer manually, not via some automatic interaction. Differences in printers are then accounted for in the printer driver thus selected.
You can enumerate the printers installed on the machine and can get information about the currently selected printer. However, I believe that much of the returned information is driver-specific. Also, you should note that simply throwing a manual switch will normally not be enough; you'll have to switch printer selections (e.g. through a Print Setup dialog).
That said, I think you can interact some with the parallel port and PERHAPS manage to do this.
Personally, I'd re-think the design and approach it differently.
Regards.
Glenn