In theory, copying the whole perl/ directory to the new machine should Just Work, but maybe you have other, external dependencies, like the database driver, ODBC connections or other libraries that are not installed below the perl/ directory.

If you go the route of doing a fresh install, the cpan utility has the autobundle command, which will create a text file that lists all modules installed on that old installation of Perl. You can then feed that old bundle to the cpan program on the new installation, and it will install all modules listed in the bundle.