If you print from a Windows program and choose to save the print output as a file, most likely you'll end-up with a *.PRN (created using a PCL printer driver) or a *.PS file (created using a PostScript printer driver).
Once you have this *.PRN (or *.PS) file, it's very easy to send them to the printer to finally get a print out:
Go to the "DOS Prompt" or the "Command Prompt"
Assuming that the file you're about to print is called my_chart.prn and your printer is connected to LPT1: (parallel port number one), type:
COPY my_chart.prn LPT1 /B
and press ENTER