Drill a conduit in the ceiling at one point?

Hello, I have a question or a "problem" whose feasibility I would like to explore. Without a reasonable solution, it remains just an idea. What I want to achieve is to install a lamp at one spot in the ceiling. Normally, this is hardly possible. However, there is an empty conduit in the ceiling. The conduit runs from one side of the room over the ceiling to the other side and was not used. I had laid it "just in case" "for all cases." I know that this conduit roughly goes where I would like to run a lamp through the ceiling. The problem is that I can only guess the exact position of this conduit within about +/- 10 cm. And I can hardly drill a hole with a 20 cm diameter and 1 cm deep into the ceiling to find this conduit and bend it downward. So it is basically impossible to do, that is clear to me. But maybe there is a trick or new technology that I am not aware of? For example, maybe going through the conduit with some kind of endoscope with a kind of transmitter whose position can then be determined exactly so that one can hit this conduit with a single 2 cm diameter drill hole? Of course, you also have to drill past the steel, which makes it even more difficult. So a kind of Mission Impossible :-) But maybe there really is a technical possibility?

The ceiling is, I assume, made of reinforced concrete? If so, then pull through electrical cables, energize them, and try to find them with a locator device.

It would work even more precisely with a radar wall scanner, but these are mostly professional devices. However, if you find one to rent (online?), you can quite accurately identify both the steel reinforcement and live cables.

Alternatively, you could also try running hot water through the empty conduit and then check the course with infrared (or thermal foil). Similar to underfloor heating detectors.

Maybe it already works with a regular hairdryer, right?

I would first knock, with the little hammer, to see if it sounds different (hollow)