https://astats.astats.nl/astats/Steam_Achievement_Info.php?A... thom-22 has the solution :
"After collecting $100,000 in gold, click the 4th button in the top left of the game window (icon looks like a document). Then click the 3rd button in the lower middle part of the game window (icon looks like a finger pointing). You now have an auto-pickup for the gold coins."