use warnings;
use strict;
#                    1         2         3         4  
#          0123456789012345678901234567890123456789012345678
my $dna = 'xxxxxxpecbcbccrlxxxxxxpeeeerlxxxxxplxxxxxPeRLxxxx';
my $re  = qr/p.*?l/i;

while ( $dna =~ m[($re)]g ) {
    print join " " => $1, $-[0], $+[0]-1, $/;
}