Why do you need to do this all in one regular expression?

Also, do you mean that the space in front of  ccc should be treated differently from the space between abc Qwerty?

Also, why does Qwerty not show up as a separate string in your other examples?

If you want a simple approach, just split the string on /[;,\s]+/ to get an array, and then get all the sub-sequences of that array:

#!perl
use strict;
use warnings;
my $string = 'aaa, bbb, ccc,ddddd;eee-12345abc Qwerty'; 
my @items = split /[,;\s]+/, $string;
for my $i (0..$#items) {
    for my $j ($i..$#items) {
        print join " - ", @items[ $i .. $j ];
        print "\n";
    };
}
__END__
aaa
aaa - bbb
aaa - bbb - ccc
aaa - bbb - ccc - ddddd
aaa - bbb - ccc - ddddd - eee-12345abc
aaa - bbb - ccc - ddddd - eee-12345abc - Qwerty
bbb
bbb - ccc
bbb - ccc - ddddd
bbb - ccc - ddddd - eee-12345abc
bbb - ccc - ddddd - eee-12345abc - Qwerty
ccc
ccc - ddddd
ccc - ddddd - eee-12345abc
ccc - ddddd - eee-12345abc - Qwerty
ddddd
ddddd - eee-12345abc
ddddd - eee-12345abc - Qwerty
eee-12345abc
eee-12345abc - Qwerty
Qwerty
[download]