Defining output file name on an exported CSV

[Robert Merrill]

I have some Sheets, selected columns of which need to be exportable as CSVs.

I found the gviz URL API and it does exactly what I want except for one thing. I want to be able to assign a name to the CSV file that is returned.

My URL syntax is https://docs.google.com/spreadsheets/d/{sheet-id}/gviz/tq?tqx=out:csv&sheet=MySheet&range=A:L&outFileName=override.csv

Everything works but the outFileName parameter; the returned sheet is always named data.csv.

I learned of the outFileName parameter in Implementing the Chart Tools Datasource Protocol (V0.6).

Where am I going wrong?

Thanks!