Bridging the gap

Sandtree

I am trying to get a cable from one side of the room to the other in the ceiling void in our flat.  We have a metal frame system so there is a series of I and U beams running along and across the ceiling which the plasterboard is then screwed into the U beams. The structural ceiling above looks like corrugated steel (though much deeper) with poured concrete above that. The frame is hung from the structural ceiling in various points. There are various trailing cables for lighting in there plus the pipes for the central heating run up the middle of the ceiling.

I've a basic set of pushrods that I managed to use for a different cable in a different area of the room across but after 2 hours today I've still not been able to get this second one done. Last time the rod was hiding on the other side of one of the U pieces but it was near to the hole so could reach around and grab it. It's difficult to start it going in the right direction as I want to go diagonal but the dips in the structural ceiling go straight across so try and make it follow them.

Is there any suggestions on how to make these things easier? Did try strapping a small torch to the end but it then wouldn't make it across the room by a long way.