ColReorder provides the ability to specify a column ordering which is not that of the HTML (which typically you will want) through the parameter oColReorder.aiOrder. This is an array of integers with the column ordering you want.
$(document).ready( function () {
var oTable = $('#example').dataTable( {
"sDom": 'Rlfrtip',
"oColReorder": {
"aiOrder": [ 4, 3, 2, 1, 0 ]
}
} );
} );