Your hash description is alarming. You do know that \%a is unrelated to hash ref $a, right?

What you call an insert into the hash is a complete re-assignment of the hash. I think you're making very clunky use of hashes, and perhaps a review of perlreftut would be helpful. At the least, you can change your statement to an insert like so:

    $Profileshoh{$prow->[0]} = {
        $prow->[1]=>{
            $prow->[2]=>{
                MIN_VALUE=>$returno[0]
            }
        }
    };
[download]

but I haven't determined whether that's What You Really Want.

Update: I think you Really Want

$profileshoh{$prow->[0]}{$prow->[1]}{prow->[2]}{MIN_VALUE} = $returno[
+0];
[download]