I've got a SSIS package which extract data from a table and writes it to a flat text file nightly. I need the resultant file name to include the date it was extracted in the format YYYYDDMM
i.e. today's file would be called: Flat_file_20091507.txt
How do I ammend the SSIS package to dynamically name the file and what expression do I need to use to produce the date in this format?