How to print from a command prompt to anything but a local printer on the LPT1 (parallel) port.

The simplest way is to pool the port the printer is attached to with the LPT1 port (right-click printer > properties > ports > enable printer pooling > pick which ports to pool).

Another way is to create a share for the printer and map the printer to an emulated local port that DOS can see, it says here.