Add a column in addition to html defined columns

mrsubby

In the following example https://datatables.net/examples/ajax/null_data_source.html we are shown how to replace a column using the columnDefs (the click button column hides the salary data and shows it in a popup when clicked).

But can we use columnDefs to add a column in addition to what was added in the html? Or do we have to put in effectively placeholder columns in the html to have them replaced with buttons/images/whatever in the columnDefs?