how do I advance filter a large csv file for unique customer #'s
 

I have a large csv file that the rows data repeats save for a couple data
elements in each row. I need to reduce the file to conatin each row that is
unique (i.e. has the same customer order number) one time and one time only (
i need all the data in that row). I need to make this fileter into a macro
that I can run each and everyday to strip out only the unique records i need.
I have read the avaiable advance filter information, but cannot get it to
work on my file. I prefer to use the copy to another area feature to preserve
the original information. Help!