Have you tried changing the z-index of the RadWindow to see if that forces it above the ActiveX control? I know Window and Dock have pretty low z-index values (as seen here
in the documentation), however I'm not sure how ActiveX controls handle z-index or if they ignore it and do their own thing.
I did find this article
from Microsoft about setting activeX controls, and it shows that you can set a Z-Index on them... So there might be hope yet!
Please let us know if this works as I'm kinda curious, but I've never touched ActiveX so I can't test this theory out.