How do I get around using a subquery in a field in PSQuery?

I had someone come to me with a request for a change to a query, to add a column with a simple 'Y' or 'N' to determine if any given student has enrolled in the term prompted. I wrote a simple CASE expression with a subquery in our SQL database, I saw it worked, so I tried to put it on PSQuery so others could access it, but I saw I cannot use subqueries in field expressions on PSQuery. I can't think around how to achieve this. I thought about writing and referencing a view, but the view would need