I passed close by you today. Several times in fact!
I was coming up the A41/A40 from Grenoble and needed to leave my hire car on the French side of Geneva airport. So I followed signs for Geneva Vallard and crossed from France to Switzerland, then got lost and found myself crossing back into France near Bellegarde. So I retraced my steps to Annemasse and crossed over into Switzerland again (luckily I left Grenoble real early) and this time went down by Lac Leman shore then north. Then... when I got near Palexpo I was able to cross over to the French side of the airport at Ferney.
The last time I did this route I also got lost and ended up paying a huge surcharge because I had to leave the hire car on the Swiss side of the airport.
Is there a simple way to do this? I wondered about following the 984 out to the east of Geneva?