The .st file contains the database structure ( areas and extents ) in ASCII, readable format. At runtime this file is not needed as the database structure is stored in binary form in the .db file, always with complete paths. Thus, when the .st file gets written out, for example doing a prostrct list or a procopy, it will always contain the absolute paths. AFAIK there is no way around that. As a workaround you can edit the .st file after it has been created and replace the absolute with relative paths.
Heavy Regards, RealHeavyDude.