This seems pretty much impossible to do. All Unreal based engines use Maps, which store the locations, object types, etc in binary data. There is no "database". Unless you can understand the algorithm (which is pretty much impossible without having the C/C++ source) in which they save the locations in those files, it would be impossible to do it.
There is no way to access objects outside of the editor without using the game. However... this might be a somewhat doable thing... if you have a dedicated PC though
One way though is to have a dedicated box running the game constantly and have UnrealScript (Unreals Scripting Language) open up a TCP port that listens for connections. You could then tell it to place a new object here or there. This would require quite a bit of vector math to find the locations of everything and place it correctly. You would also then need it to save out into a file for locations if you wanted it to save it if the game was shut down.
Im sure that just confused the waffles out of you, but i hope it helps. Do as Wormbo says and download
this
That is the UScript source. It can help you in making the project.