#!/bin/bash

interface=dev0
mycommand="sudo openvpn --config '/etc/openvpn/optionFile.ovpn'"

$mycommand

Options error: In [CMD-LINE]:1: Error opening configuration file: '/etc/openvpn/optionFile.ovpn'

#!/bin/bash

interface=dev0
mycommand="sudo openvpn --config /etc/openvpn/optionFile.ovpn"

$mycommand