<%init>
use XML::Simple;
my $xref = XMLin("path_to_xmlfile.xml");
my $newnode = {};
foreach my $kee ( "uid", "company_name", "contact_name",
"contact_phone_number" ) {
  $newnode->{$kee} = $ARGS{$kee};
}

foreach my $rec ( @{$xref->{record}} ) {
  if ( $rec->{'uid'} eq $newnode->{'uid'} ) {
    $rec = $newnode;
  }
}
</%init>