use strict;
use warnings;
use XML::Simple;
my $TGROUP = { 
     COLS    => 4,
     COLSPEC => [ 1, 2, 3, 4 ],
     THEAD   => { head => "head" },
     TBODY   => { body => "body" },
};
print "<TABLE>\n";
for ( qw( COLS COLSPEC THEAD TBODY ) ) { # in your desired order
     print XMLout( {$_ => $TGROUP->{$_}}, RootName => $_, KeepRoot => 1, NoATTR => 1 );
}
print "</TABLE>\n";