There are several ways you can do this. The way I usually do this is to FTP the file down to a working directory, and then use a ForEach Loop to process the file (or files, if more than one) from that working directory. Once the file is processed, you can use a File System Task to move the file from the working directory to an archive directory.

Feel free to post more info if this won't solve your problem.

hth,

Tim