Installing cables afterwards in prestressed hollow-core concrete slabs

I am currently facing a (home)handicraft challenge ;-)

Here there is an outbuilding with prestressed concrete elements as the ceiling. These have a V-joint, as one might know from prefabricated element ceilings in single-family houses. A cable for a ceiling light is to be laid in this joint, which will be plastered over afterwards.
Now gravity is a annoying matter and I am completely stuck right now: How do you fix the cable "up there" so that you can plaster over it later? Something sticky to hold the cable temporarily?
Hammering cable clips into concrete?
Plaster it directly and press the cable into the setting plaster?

It is a rigid cable, about 5 meters long.
Who has a practical tip?

I would start with a try using construction adhesive. Clean the concrete beforehand.