One of the bolts that secures the running board/nerf bar (oval type, Ram logo on step) to the frame backed out. I took one out from the other side to match it up at the hardware store, and now I can't get them back in. They must of been fastened to some sort of nutplate. Does anyone know about this, and how to fix it? Any advice would be appreciated.

PS - I stopped by the dealership and a guy in the parts department said they only sell the whole running board kit, and made the suggestion to do what I explained above.