It depends on the control, but in general, PowerBuilder 12 (and previous versions) can easily use external controls through OLE. You add them to your application through the menu item "Insert โ Control โ OLE", after which you will be asked to select a list of the registered object for selection.
When encoding, you will need to use an object reference or exact notation to reference properties and / or methods. Everything works fine in PB, but it's not as convenient as you can't use named arguments, and you just need to get your syntax (and throw exceptions) to avoid null link failures.
Hope I understood your question correctly and that helps.
Regards, Rich