Thanks tedrek for the excellent code, I slightly modified because I like to 'sort' within account block 
my @oldlist = map {chomp; $_} <DATA>;

my @sorted = map {$_->[2] . " " . $_->[1]}
             sort {($a->[0] cmp $b->[0]) || 
                   ($a->[2] cmp $b->[2]) || 
                   ($b->[1] cmp $a->[1])}
             map { [split] } @oldlist;

#print join "\n", @sorted,"\n";

my @newlist = map {shift(@oldlist) . ' ' . $_} @sorted;
print (join ("\t", split),"\n") for @newlist;
__DATA__
a1 p1 qX5
a1 p1 q6
a1 p2 q4
a2 p3 q9
a2 p2 q8
a2 p2 q9

_OUTPUT__
a1    p1    qX5    q4    p2
a1    p1    q6    q6    p1
a1    p2    q4    qX5    p1
a2    p3    q9    q8    p2
a2    p2    q8    q9    p3
a2    p2    q9    q9    p2

[download]
Notice that 'qX5' remains within the given block of account (a1).

artist

In reply to Re: Re: Adding Columns from Given Data by artist
in thread Adding Columns from Given Data by artist

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