@Pappenheimer: Thanks for the answer. The Problem is that i can not use this method in an editor as i do not want to edit mdl files, just for edit the scaling of an object.
This sounds a bit like trying the impossible, because every result of a manipulation within the editor must work without problems in the engine without sacrificing the framerate.
This means, IMO, that the engine must provide such a function to assure that it is actually of use in realtime.
It makes no sense, if it works in the editor, but not in the engine.
Or, did I miss something?