There are loads of ways of doing it.
How a level is saved will depend greatly on what specific things you need saved, and how the game will interpret them.
One way to solve your specific issue is to store a position and a rotation, either as some floats and some rotation angles or something, or by basically having the entire 4x4 matrix stored in the level's file.
ObjectName = "MyObject"
ObjectType = "AwesomeObject"
ObjectPos = 100.023f, 39.5f, -882.0f
Then, in this example when loading, the editor/game would see a new object block (from the "Object_Start" keyword), would assign its name and type based on the next keywords, and put it in the exact position you wanted it, based on the position data.