Dont worry solved it :)... create a npc_metropolice setting him to rappel and flagging him as a template, then make a npc_template_maker below him and set it as disabled. use a trigger_once to enable the maker and then set an output on the npc_maker to tell the npc_metropolice to onspawnnpc - beginrappel.
could'nt wait for you guys, had to solve it, it was bugging me
7rip$ter.