方法を見つけた
var controller_name = '<?php echo Zend_Controller_Front::getInstance()->getRequest()->getControllerName();?>';
"fnDrawCallback": function ( oSettings ) {
/* Need to redo the counters if filtered or sorted */
for ( var i=0, iLen=oSettings.aiDisplay.length ; i<iLen ; i++ )
{
var link = $(' <a href="/'+controller_name+'/modifica/id/'+ oSettings.aoData[ oSettings.aiDisplay[i] ]._aData[0]+'">Modifica</a> <a href="/'+controller_name+'/cancella/id/'+ oSettings.aoData[ oSettings.aiDisplay[i] ]._aData[0]+'">Cancella</a>');
$('td:eq(0)', oSettings.aoData[ oSettings.aiDisplay[i] ].nTr ).html( i+1 );
$('td:eq(0)', oSettings.aoData[ oSettings.aiDisplay[i] ].nTr ).append(link);
}
},