Mount new headliner with sliding sunroof

Hi Everyone and a Merry Christmas from Sweden
I´m about to mount a new headliner in my car with sunroof. Problem is that I don´t have the old parts, it was all gone when I got the roof.
Anyone that knows what length the rod should be that sits where the red line is ?
Anyone that has any pictures from this kind of job (with sunroof) ? or tip or trix Best regards
Nick