There are different ways to achieve that, depending on your skills and application requirements:
- use an ActiveX control that does all the work for you in its own Window (http://www.idautomation.com/
- use a special font that will substitute your characters with bar/space sequences (http://www.adams1.com/fonts.html
- do it yourself by creating a bitmap image with bars and spaces computed using the rules in the standard.
What way do you want to go ?