Hi,
good news: To use that DataTables functionality, you won’t have to deal with custom code.
Instead, just use the TablePress Extension from http://tablepress.org/extensions/datatables-columnfilterwidgets/
To use that separation value, you will simply need to add another parameter to the Shortcode, like
[table id=123 datatables_columnfilterwidgets=true datatables_columnfilterwidgets_separator="," /]
Regards,
Tobias