Does CR allow you change the directory that the database is in, easily?
are the files produced flat and can then combined to make 1 'big' database?
If you want to run for multiple dates, they should be in the same database, preferably in the same table. This is what CR is expecting, one table with lots of data.
can you make something like a stored proc, whereby you pass in the dates, and the procedure goes to the different files and retreives all the data into larger tables which are then returned to CR?
I don't know anything about dbf files and their structure, but if you could accomplish either option, CR would be much happier, and your life writing the reports would be much simpler.
HTH