c:\@Work\Perl\monks>perl -wMstrict -le
"use 5.010;
 ;;
 use Data::Dump qw(dd);
 ;;
 my $s = '\"word1\",word2,\"word3,word4\"';
 ;;
 my @ra = $s =~ m{ (?| \"([^^\x22]*)\" | ([^,]+) ) (?:,|$) }xmsg;
 dd \@ra;
"
["word1", "word2", "word3,word4"]