I created a Dialog-based MFC app. The dialog boilerplate is used to manually start USB controlled hardware functions, which usually execute repeatedly, with various hardware parameters being changed by the function modules as they execute. Headers for these functions are Included in the Dialog header. Everything works ok, no problems. The app could be likened to a data logger. But, now I want to display measurement data as it is produced, "simply" writing it to an Edit Box on the Dialog. Unfortunately I have not been able to devise a method to achieve this. I can see that the problem is that the functions which need to update the Edit Box are "downstream" of the Dialog. Any tips or pointers to similar Dialog apps (where the action code is not coded as part of the dialog) would be greatly appreciated.