Total Commander

Can stay on top function be added to TC with a hotkey? Once in a while it comes on handly. I now need to use an additional software just for that.

What's wrong with additional software? That way you have nice consistent way of making windows on top in any application you might ever need. Seems to me as much simpler approach than convince authors of several applications to add separate on top function. Or is TC the only application you need to make on top? :)