Your focus appears to be all wrong. If you are looking for something specific in a file why not just select that thing?

my @output = ();
while(<DATA>){

    next unless (m/DATA/);
    my $line = $_;
    while($line=~m/(DATA\d+)/g){
    push @output,$1;
    }
}
print join qq|,|, map {qq~xxx=$_~} @output;
print qq|;\n|;

1;

__END__
TABLE NAME

HEAD0 HEAD1 HEAD2

DATA00 DATA10 DATA20

DATA01 DATA11 DATA21

END
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Produces...

xxx=DATA00,xxx=DATA10,xxx=DATA20,xxx=DATA01,xxx=DATA11,xxx=DATA21;
[download]