package MyCgiApp;
use base 'CGI::Application';
use CGI::Application::Plugin::Scotch;

# at this point, MyCgiApp should behave as if 
# CGI::Application::Plugin::Session was imported into the 
# package.

##</code><code>##

package CGI::Application::Plugin::Scotch;
use CGI::Application::Plugin::Session;
use Exporter ...
@EXPORT = qw/scotch session/;

##</code><code>##

package MyCgiApp;
use base 'CGI::Application';
use CGI::Application::Plugin::Scotch;
use CGI::Application::Plugin::Session;