Is it possible to modify `{% tracking_code %}`?

[mikbuch]

This works for me now. Thanks for it.
Can you tell if it is possible to modify {% tracking_code %}? For example how can I add
_paq.push(['setDownloadExtensions', "csv|xls"]);
to it?

Reported by: @mehrdadscomputer here: #6 (comment)

[BrianPainter]

+1