Jay,
Thanks for the inquiry. Is there a specific protocol or format you are trying to work with? Are the frame size fixed in length or variable? The answers to these questions will dictate whether you can use an existing block or if you will need to write your own.
Writing a block to parse things after the correlate access code block is relatively straight-forward. If you are using the (tag) version of that block, you simply need to look for the presence of that tag to delineate the start of a frame.
-John