Burak & Charles:
Thanks for your help. I think I've re-familiarized myself with Perl adequately for the time being.
For what I'm doing now, I didn't really need global "variables", but only constants, so I've set up the config module like this:
package MyDefs;
...
use constant DEST_BASE_DIR => 'c:/backup';
use constant LOCK_FILENAME => "@{[DEST_BASE_DIR]}/backup_lock";
use constant LIST_FILENAME => 'backup.lst';
use constant CMD_FILENAME => 'backup.cmd';
...
1;
Then in other modules, I can reference the constants like this:
...
use MyDefs();
...
open(my $fh_lock, '>', MyDefs::LOCK_FILENAME);
...
my $cmd = "$dest_dir/@{[MyDefs::CMD_FILENAME]}";
...
