I had the same issue myself. I went to many different hardware stores and had no luck finding a replacement screw that fit. But I finally searched and found these that worked great for me: [link removed per forum guidelines]
Hope it helps solve your problem.
Thanks MadridPhotos. I ordered from that site and the screws work perfectly in fixing my G7x screen issue. If anyone is having problems finding this screw at their local hardware store, I suggest just buying from this site.