Consider having your second process (which requires %ENV variables to be upper-case) to explicitly use uc on all such references.

For example, my $svr = uc( $ENV{DBSERVER} );

This enforces the upper-case requirement on the only process that requires it, and doesn't impact anything else.
Please ignore. It's the subscript to %ENV that needs to be upper-case, not the value of %ENV that needs to be upper-case.