if you do in fact want to explore mod_perl, then
Apache::Registry is the closest you will come to the
CGI.pm framework under mod_perl.
however see "Web Application Framework" elsewhere on
the monastery for a discussion of more user-oriented
frameworks.
frankly, for me, mod_perl is too nuts-and-boltsish.
I like HTML::Embperl, a mod_perl enabled framework which
can make use of mod_perl modules when necessary and has
single-tier access to Perl modules unlike other solutions
which require that wrappers be written for every pure
Perl module/function you want to use.