CPYFRMIMPF and nulls

I'm getting records from a PC application with data like this:
A,B,,D

The 3rd column is blank.

I used Client Access to upload the data to a table created by the CAX wizard.

When I use CPYFRMIMPF to load the data in production mode, I'm getting hammered 
because F3 (column 3) is NOT NULLS and two consecutive commas indicate a null 
value.  I'd rather see blanks.

Short of getting this file recreated or of using ALTER TABLE to make the 
columns null-capable, is there any way around this problem?

Thanks,
Reeve