after reading your problem again today and reading paul's response, i see i misinterpretted your need. i agree with paul's response. paul states correctly:

"Since SSIS moves data through the process in Buffer pages you can't set the output of a row to have a dynamic destination within the same buffer. All rows in a buffer will go to the same destination. If you need to output rows to different destinations then you somehow have to take all rows for that destination and move them together. @ ways for example are

1) A conditional split task with logic to output records that go to the same destination together. Say you wanted to output files based on state then you would have 50 Conditions in your Conditional Split with 5 outputs. Each of these outputs would then map to a specific destination..."

the conditional split can direct the individual rows in the buffer to different flows based on the contents of that row. then a script component in each resulting flow can dynamically generate the file name for the destination in that flow. see pic for visual representation