Select multiple columns in QueryDSL JPA only if columns are present in a Collection

I have a list of columns as List<String> columns, and I would like to retrieve those columns using queryDSL.

I have this working-

   queryFactory = new JPAQueryFactory(entityManager); //where entityManager is a JPA EntityManager
   JPAQuery<?> query = queryFactory.query();
   QEmployee employee= QEmployee.employee;
   List<Tuple> result = query.select(employee.firstName, employee.lastNameemployee.lastName ,employee.age)
                .from(employee)
                .fetch();

This works fine in my test. But here I am specifying the column explicitly in the select(..) part. If my List has only firstName and age like

List<String> columnList = Arrays.asList("firstName" , "age");

then I only want to retrieve those two column from my select(..) part. QueryDSL select part only accepts Expressions, so I tried doing this:

 StringExpression[] columnListExpression =  columnList.toArray(new StringExpression[columnList.size()]) 

and then passed columnListExpression to my select(..) part as shown below,

   List<Tuple> result = query.select(columnListExpression)  // doesn't work
                .from(employee)
                .fetch();

however I get a Unsupported Operation Exception. I wanted to use queryDSL because that way I can easily construct the Predicate at runtime in a type safe manner. This SO question brushes the topic, but it was 5 years ago and now we have QueryDSL 5.0 How do I select only those columns that are present my List using queryDSL?

Something like this worked:

PathBuilder entityPath = new PathBuilder<>( Employee .class, "entity");

List<com.querydsl.core.Tuple> employeeResults = query.select(

entityPath.get(" firstName ", String.class)

,entityPath.get("age", Integer.class)) .from(entityPath) .fetch();

BUT I don't know the columns before hand and need to construct this select(..) part dynamically.

Can anyone please help? I'm sure many others would have had this problem of coumn multi-select?