>perl -wMstrict -le
"my $s = 'KE a KE bb ccc KE ddd PA ee KE fff xx PA gg KEPA h';
 my $start     = qr{ KE }xms;
 my $not_start = qr{ (?! $start) . }xms;
 my $stop      = qr{ PA }xms;
 my $chunk     = qr{ $start $not_start* $stop }xms;
 print qq{'$s'};
 print map qq{'$_' }, $s =~ m{ $chunk }xmsg;
"
'KE a KE bb ccc KE ddd PA ee KE fff xx PA gg KEPA h'
'KE ddd PA' 'KE fff xx PA' 'KEPA'