Having just re-installed Linux Mint 18.2, I realize that the information I provided was incorrect.
For that, I am profoundly sorry.
In the first place, the OpenVPN plugins required by the Network Manager are installed by default.
In the second place, the procedure outlined by rbsudo is spot-on correct and should work for whatever the usual source of connectivity might be, wired or wireless.
I have re-learned two valuable lessons through this:
1) ALWAYS confirm your facts, NEVER ASS-U-ME
2) Heed the words of Abraham Lincoln when he said: "It is better to remain silent and be thought a fool than to speak out and remove all doubt."