use strict;
my $str = 'APDNUDES_F2013_Sammi-Tye-in-Beauty_V190522172041.mp4
APDNUDES_F2013_Sammi-Tye-in-Classic-Curves_V190522161615.mp4
APDNUDES_F2013_Sammi-Tye-in-Classy-Erotica_V190522173336.mp4
APDNUDES_F2013_Sammi-Tye-in-Classy-Erotica_V190522173336
';
my $regex = qr/APDNUDES_F20[0-9]{2}_((?:[A-Za-z]+-?)*-in-(?:[A-Za-z]+-?)*)_[P|V][0-9]+(\.[\w]{3,4})?/mp;
my $subst = '${1}${2}';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html