Practically speaking, you almost certainly won’t use CL nor RPG to do this. You’ll use Java and JDBC. You would use ILE RPG to invoke the Java methods, though, and possibly use CL to call the RPG.
Microsoft’s implementation of ODBC was originally kind of a proprietary superset of a subset of the open DRDA specs. And AFAIK, the only driver MS has made available for i5/OS is their Type 4 JDBC driver.