Hi Jason:

I did this for a client a number of years ago.
The trick is that you need to install a bar code font on each workstation that you will print the Order from.
I think that the font we used is called: IDAutomationHC39M

First, add the Order Number to the spec where you would like it to appear.
Following this, change the font to the bar code font.
That’s it.
Note that you may have to experiment with the size of the field.

Contact me if you need assistance.