Specific structure? No, but I think if you reduced the hyperspace exit radius it would shorten the general build range for that specific gravity well.
moveAreaRadius 48000.000000
hyperspaceExitRadius 40000.000000
That is located in each of the planet entity files. Combine that with placementRadius located in each of the structures entity files and you might find what you are looking for.
placementRadius IIRC is a value of how close the structure can be to another structure or planet. Maybe try to make this larger than the moveAreaRadius would force the structure to be built closer to or farther away from the planet.
Let us know what you find.
