How to modify "resources.assets" (or alternative?)

Hi, is there any way to add/remove files to/from the resources.assets file?

I would like to load prefabs from external resources during runtime. Of course I thought about AssetBundles, but unfortunately I can't afford Unity Pro.

I thought I could achieve this with Resources.Load() until I noticed that I can't just put files into the "Resources" folder and load them after building the game.

Maybe there is another very different approach that I don't know?

Thanks in advance!

EDIT: I found an ugly and complicated yet possible method to "inject" external assets in the game. In the game I create, for example, one main scene and 50 empty scenes and then build the game. If I now have (from another unity project) one empty scene (as the first) and (as the second) a scene containing the assets I want to load in my game I can build this project and get two important files: level0 and sharedassets1.assets (must be at least two scenes in order to get the level0 file). I can now replace one of the empty scenes in the game with these files and load their contents with Application.LoadLevelAdditive(), so the point is: Scene = AssetBundle! Maybe it is helpful for someone, for me it works.

Almost certainly not possible without knowing the internal method for creating the binary data. And even then I'm not sure it'd work.

You can use WWW class to load any data after building you project.