Is it possible to read the text within the Details tab of TestDirector? The closest thing I could find is "TDAPI_GetDesStepValue" which is only available for TestDirector 6.0 (we're using WR 7.5, TD 7.2).
Where are you trying to use this data? I am more comfortable with SQL queries for now as I am not that familiar with ALL the API calls yet. I would execute this query once connected:
Maybe this will get you started.