use strict;
my $str = 'Schoenen US 30 /
Dames US 30 /
Dames US w30 /
Heren US w30 / L34
Dames US L /';
my $regex = qr/^(?:dames|heren|schoenen us)\s+([a-z]*\s*)(?:([a-z]+)[\s/]*$|\D*(\d+)(?:[\s/]*$|(\s+\/\s+)\D*(\d+).*$))/imp;
my $subst = '$1$2$3$4$5';
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