I guess that Anonymous Monk wants you to explore stuffing subroutines into the DB package which is magical to Perl. At a cursory glance over perldebguts I at least find DB::postponed() which is called after a file is required but before it is executed, this might or might not help you, as you are quite unclear on what you actually want to do, except "differentiate between use and require", and your current solution does not tell me how you differentiate between the two with it.
Update: Aristotle's idea of naming the module Package::CodeDumper makes it far more clear to me why you want to distinguish between use and require - you want to create code that looks "mostly" similar to the module as loaded from disk resp. as created by other means. This would be beneficial for caching of DBIx::Class or Class::DBI modules for example, and of course for debugging such dynamically created namespaces/packages.