When creating a new .ttf, how does one go about exporting "Smart Quotes"?

I'm trying to insert smart quotation marks into my .ttf.  Should be "8216", "8217", "8220". & "8221" which fall under "General Punctuation" Character Block, but I get the error message "Exporting this character code to a Symbol Font is not supported".   Is there some other option that I can use for Smart Quotes?