Yes, look at ajax buttons mColumns
option :
This parameters defines which columns should be used as the data source for the export. The parameter can either be a string with a value of 'all', 'visible' or 'hidden' - or an array of integers with the column indexes to be exported.
This default value is all
. In the options, define the CSV download button like this :
...
oTableTools: {
sSwfPath: "path-to-your/copy_csv_xls_pdf.swf",
aButtons: [
{ sExtends : "csv",
mColumns : "visible"
}
]
}
...