use strict;
my $str = '"87",0000,0767,"078",0785,"0723",23487, "061 904 5284","17\\/10\\/2016","some.name.789@hotmail.com"';
my $regex = qr/(?<!")(\b\d+\b)(?!")/p;
my $subst = '"$1"';
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