you can't crossover things like that in source games, at least not with outmaking a mod from scratch.
YOU LIE!http://i21.photobucket.com/albums/b271/Dagoth85/SyringeJump1.jpgJust kidding. That is a custom map call cp_skyscraper and I am not sure if that is a functional portal or just a decoration. It looks too big to be a spray.