If you’re asking about where the pin is placed when you click the “Gmap” link and it opens the Google maps page, then the answer is, Mostly, no. The Gmap function just opens an external Google Map to the listed street address for the supercharger and Google will place the pin wherever they “locate” that address, SC.info can’t change where Google places it. The best that can be done to manage that issue is to use a street address that Google locates as close to the right point as possible. In this case I think changing it to the address for the Burger King is about the best that can be done:
12 Rue des 11 Arpents, 41000 Blois, France
But since there aren’t any addresses that are locate in the green area you marked, we can’t get it closer than that for the Gmap link. On the SC.info map we can place the marker exactly.