How do I present a verification process that resulted from an action in a modal dialog?

I need to create a modal dialog (one that comes form the system) which asks for the license key and when confirmed there should appear a verification icon to indicate progress (although this would not take long - but users need feedback in case of lack of internet connection and so on, right?). So where do I provide this verification icon? I don't think I can put a window on a modal window and I can't put verification progress bar/icon inside a modal window either.

Similar solution would apply when I need a modal window asking if the user is sure to abort a process and then there should appear a progress indicator of aborting/cancelling this process.

What do I do?