mod_perl handlers allow you associate arbitrary locations with your code. Consider this snippet. It uses a redirect so requests for the root go to the script's URL and from there I've associated /opencivics with the OpenCivics::WebApp::handler() method.

Redirect /index.html http://www.somewhere.org/opencivics
<Location /opencivics>
        PerlSetEnv ALZABO_DEBUG ALL
        SetHandler perl-script
        PerlModule Apache::Request
        PerlModule OpenCivics
        PerlHandler OpenCivics::WebApp
</Location>
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