You can't. The buildings definitions are within the definitions for the outdoor areas, which are the .odm files. Neither of those editors even expands the information for those files and it probably wouldn't do you a lot of good if they did. The only thing those editors would do to help you is that the extract the contents of the .lod files. After that, you would have to go into the .odm files and manually add the information with a hex editor.
A program could be written to do it, but it would take a lot (I mean a whole lot) of work. I don't think you got the thrust of my last reply - it's theoretically possible to do it. There is no practical way to do it at the moment.
i.e. for all practical purposes it can't be done right now.
