I'm sorry, but without seeing your code, and your data, the output you get and the output you want, I can't really help you there.

Maybe you can explain things better if you post real, runnable code and data for that program, because for me, the following just works as I imagine it should:

#!perl -w
use strict;

my $data= <<EOM;
firstline
secondline
data_hereDATA THAT IS CAPTURED
EOM

$_= $data;
my($result)= /^data_here(.+)/m;
print $result; # DATA THAT IS CAPTURED
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