I haven't tried it with VFP and WinFax 9.0, but I have a Fow Win 2.6 and WinFax 7.0 program using DDE to fax order confirmations every evening. It steps through a table of about 50 orders, DDE pokes a phone number, prints a report (the order confirmation).

Getting the DDE sysntax just right was a minor nightmare, but once conquered it works.