When you say you want this stored as a scalar, and assuming you've got multiple records, how do you want to preserve the relationship in the data? There are various method to do this however what you've got here looks pretty good IMO.
Having never worked with MS Access and the DBI, I cant comment on how (or if) it actually works, however if it works the same as a "regular" ole DBI supported database, i'd be using a simple sql and placeholders to insert this data into your database.
There are many nodes here you can lookup examples for...