use strict;
my $str = '90,91,90-200,90,900-9000';
my $regex = qr/^(?=.*?[1-9])[0-9\\,\\-]+$/p;
my $subst = '';
my $result = $str =~ s/$regex/$subst/r;
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