Single quote (apostrophe) dumb vs. smart display

Hello,
I am producing software documentation that contains snippets of code that users should be able to cut and paste into other applications for execution.
Some of the snippets contain single quote characters. These originate as the keyboard single quote/apostrophe character (ascii #27). My production process involves converting the source document into PostScript and then converting the PostScript into PDF.
After the conversion to PostScript the single quotes are still ascii #27 characters. But after the conversion from PostScript to PDF the single quotes have been converted from the "dumb" keyboard character to "smart" quotes - ascii #92. These of course are better looking that the original, but when cut and pasted into another application cause it to fail since it doesn't recognize them as single quotes.
Is there a way to turn off this feature? And in particular is there a way to turn it on/off based on the current font?
In my case the conversion from dumb to smart quotes is fine in running text, but when the font has been changed to courier (monospaced) to represent code I want the quotes to remain in their original state.
I did try a simple experiment of converting a plain ascii file directly to PDF. In this case the single quote characters remained in their original state (ascii #27). Also, double quote characters (ascii #22) come through either path, ascii to PDF and PS to PDF, without being changed.
Thanks,
Craig