Need vent latch

No name brand to be found on these windows anywhere. I need a vent latch but as you can see there's only about a half inch of space. I'm afraid if I drill into this area I may hit glass. Is that area hollow, or does the glass go beyond the pane and into this area making it impossible to drill into? If it's hollow, will a 26-122 work, or a 26-219?
Thanks