I don't think this is possible with Wappler. I asked a similar question here and George commented:
You can’t create dynamic sql with them like having dynamic column names or sorting order based on parameters... This is how PDO prepared statements work with their parameters.
I appreciate this is to with PDO Prepared Statements, but it's a big limitation of custom queries. I think there are ways round this - while maintaining the security advantages of parameterized queries.