Usually Not-Matched records are generated because of an exception in data or the lookup table does not have the current snapshot of the data you are loading.
i would suggest if you are getting not matched rows you 1st insert/update the lookup table 1st. by doing this if you still get not matched records then that will be your true exception. dump it in a file or in a Error log table for further investigation.
Having said that to answer your question. Yes you can do that i-e Matched record 1st and Not-Matched buy doing this
1. Create a separate table ( something like "ItmNonMatch") to hold the Not-Matched records. No change is required for the Matched records insertion.
2. Create a new DataFlow OR you can also create a SQL Execution Task and perform your transformation and insertion in that task.
hope it helps.