It's quite easy, and it works regardless of any brand or driver, because it is internal programming only. First you have to build a button subset like a popup, arranged in front of the page design, where it appears. Then you have to set the visible state flag within the variables tab to a flag you want (for instance flag 256) for all buttons which are used at the popup subset. After that you can set or clear the flag in macros where you use volume actions. Thats all about this little secret.