Creating a dll from project


I want to create a game project which can be used as a module, as a dll by other software. The role of this project is would be when used to recieeve some configuration, instantiate actors in a scene, do time evolution and report back some data to the calling software. So it would have an interface and other software can link against this library. Can you please point me some documentation on how to make dlls and not executables from unreal project ?