How to create a custom sort key

How to create a custom sort key

I'd like to be able to sort data in a view by a custom key (i.e., not by a standard alphabetical, numerical, or date sort).  I'm a pastor, and have an application that I have developed to keep track of my preaching schedule.  It has the following forms (among others):
  • Sermon Series (each entry is a separate sermon series)
    • Field: ID (autonumber integer)
    • Field: Series Name (string)
    • Field: Description (rich text)
  • Sermons (each entry is a distinct sermon)
    • Field: Sermon Date (date)
    • Field: Sermon Series (lookup field tied to the ID in the "Sermon Series" form)
    • Field: Sermon Name (string)
    • Field: Description (rich text)
I have created a list view that aggregates this data sort of like below, with the data grouped by the fields "Series Name" and "Series Description"

Series name --> Series Description 
  Sermon 1 (details) 
  Sermon 2 (details) 
  ... 
Series Name 2 --> Series description 
  Sermon 1 (details) 
  Sermon 2 (details)
  ...


The only problem with this is that the view is sorted alphabetically by "Series Name."  I want the data sorted by date, but still want to maintain the grouping by series name.  This was easy in MSAccess, as I had a series of queries that determined the date of the first sermon in a particular Sermon Series and then based the report sort order on that.  I'm not sure how to do this in Zoho Creator.  Any suggestions would be helpful.