I can't help myself, even though I'll probably lose XP. Why in the name of whatever_deity_you_like wouldn't you just say:

$item="heat741a" ; 
$OrderQty = 55;
  open(LOG, ">order.xml") || die "Can't open the log file: $!\n";

print LOG  qq(<?xml version="1.0"?>
<order>
<product>$item</product>
<quantity>$OrderQty</quantity>
</order>);
[download]

I never use formats unless I want something that automatically paginates or wraps blocks of text in columns. Update: removed trailing \n which might have caused well-formednes complaints.