I am no guru on electrical systems but yes Daz .
Guess the easiest way to do it is to take the 12v + feed for the fog switch from the dipped beam 12v + feed .... Somewhere near the steering wheel to help keep the cables tidy !!
Another option woud be to take the feed from the light switch .... The one with the Off / Side lights / Headlights
That way you should have power to the foglight on both dipped & main beam
Like I say, no expert .... I just tend to bumble along & cross each bridge as I come to it
