You wouldn't have to redo much... just remove the insert server behavior and apply the insert server behavior from DataAssist... the rest would still work.
If you want to add it, then somewhere in the code, after the insert takes place, add code like:
if (!session_id()) session_start();
$_SESSION["NewID"] = mysql_insert_id();
then on the next page, or any page after, you could refer to that session variable for the last inserted id.