Two problems with your question 1. The Enterprise was in orbit of the planet the whole time. Data and Picard knew which planet Soran would be on so of course they would orbit the right planet. 2. The Enterprise never beamed him down to the planet his signal was relayed through the Klingon transporter so they wouldn't give away Soran's location. When suggesting the prisoner exchange Picard said he would beam to the Klingon ship and have the Klingons beam him to Soran's location.they travled to veridian 3 first THEN beamed picard down. Also, they beamed him to the Bird of Prey, which beamed him to the surface.
I think you've missunderstood something about the climax of the movie, all the action takes place on and in orbit of Veridian III.