I think we may need some pics to be sure we`re talking about the same parts...
2 of these for the front guide rail. they are pushed through the glass and the square part is screwed on. the head of the screw will be inside the rail.
up stop ,down stop
these are from hamtrack registery... very handy
when the glass and front guide rail are in the door ,you can place the rear guide, then the regulator and horizontal guide rail.
Maybe it`s possible to do it your way, but since I`m not 100% sure I know what you mean, I really coudn`t say
let me know if you need more help.