Hmmm. It looks to be expected from a 22 year old jeep. One option is to go with a completely new windshield channle (just an option, I didnt say the best), another option would be to hammer down the pushed up metal and put in new self tapping screws, you could re drill the channel in other spots so your not screwing into the same old metal, I think your best bet would be self tapping screws screwed into fresh(er) metal but get some paint on that rust and seal up those holes before your windshield frame turns to dust.
DD- 1995 YJ 2.5L, Cat delete, 19lb injectors, 30/9.5r15
Trail Rig- 1994 YJ 4.0L, Rubicon Express 4.5inch lift, 1inch body, D30 Aussie, 33/12.5/r15 Cooper Mud Terrains, front bumper, rocker guards