There's no way to know where a line starts, so you have to read the file until you find the line. 
my $id = 'data4';

my $result;
while (<$fh>) {
   /^\Q$id\E\s/ or next;
   ($result) = /\s(\S+)$/;
   last;
}

die "not found" if !defined($result);

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In reply to Re: random search in file by ikegami
in thread random search in file by Anonymous Monk

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