Porting of objects (creatures, terrain and items) is based upon the conversion tables. Said tables envisage no customization of any object. This is not helpful when the best scenarios feature a lot of customization of objects.
Currently the tables are hard-coded, written into the Editor program itself. They are found in the header file Bl A Fileio.h.
Porting a heavily customized scenario requires the ability to alter the header file and then compile the program, something not everyone will be familiar with.
Two approaches are possible here:
(1) tables are no longer written into the program. Instead the program reads them from an external file.
(2) tables in the scenario editor are patched by a slab of data, which could be written with a spreadsheet. Actual patching is done by a hex editor. In my last version of the Editor, most of the tables were found after offset 595,423.
Version of Bl A Fileio.h found at the Halls of Chaos SVN repository has been customized for one scenario only: Shadow of the Stranger. This will need to be corrected.