Hello,
I solved it using the below line of code.
"buttons": [{
extend: 'excel',
exportOptions: {
orthogonal: 'sort'
},
customizeData: function ( data ) {
for (var i=0; i<data.body.length; i++){
for (var j=0; j<data.body[i].length; j++ ){
data.body[i][j] = '\u200C' + data.body[i][j];
}
}
}
}],