I am looking into adding recurring task support into the Outlook client. Outlook has a bloated recurrence model (which I am still getting my head around) that is going to be hard to map to the simple repeat option.
Could you please give me some more information about the format of the rep_advanced string from the Edit/Add task API:
rep_advanced : A string indicating how you would like the task to repeat if the simple options will not work. For example: "Every Monday".