Hi @André Cruz 

What have you tried so far from the Wijmo APIs?
Currently, the data grid team is not considering having this feature as a single client action.
The principle is to leverage the existing atomic client actions and have developers use them to create more complex use cases - all about extensibility.
You can explore this interface and implement your own custom, with something like this callback provided:

wijmo.grid.xlsx.FlexGridXlsxConverter.save(grid, {
       includeColumns: function(column) {
                                                 return column.binding !== 'country';
                                      }
}

Best Regards and share your findings with the whole community,
GM