Sending a custom class to an ActiveX callback VI

[pobrepablo1]

I have a bunch of numerics / bools / strings I needed passed to an ActiveX callback VI (via the Reg Event Callback primitive). So, I used "To More Generic Class" and put them all as "Generic" then put put them in an array as the  primitive's Parameter. I typecasted them back in the callback VI via To More Specific Class (this the best method?). That worked fine. 

But now I want to also pass a custom labview class I have made. I can cast to generic, but I can't seem to get it back on the other end - how does one go from generic -> MyCustomClass type? See the image for what I want to do. 

[pobrepablo1]

Here is array I'm working with

[pobrepablo1]

OK well I managed to get this to at least compile. Not sure if this is "correct" - I just made a dummy control of the class I wanted, then right-clicked to make a reference, then used that. Seems pretty inelegant.