CONNECT: special char for NULLs

As far as I understand, there is no way to tell CONNECT that a special character in a file represents NULL.

Please, take a look at this example. It's an open dataset from Italian government, and the same format is used for several other datasets:
http://www.dati.salute.gov.it/imgs/C_17_dataset_7_download_itemDownload0_upFile.CSV

The column DATAFINEVALIDITA is a DDMMYYYY date, and '-' represents a NULL value.

If I may suggest, a new column option would be a great solution:

col_name DATE null_value = '-',