You can use the keyboard... to start a macro doing this!
With AutoHotkey:
#^x:: ControlSend Edit1, {Enter}, ahk_class IEFrame
Win+Ctrl+X to refresh the window.
Note I have the following settings in the script:
SetTitleMatchMode RegEx
SendMode Input
It works, even if the window hasn't the focus.
You can also do a loop for periodic refresh.
Problem: the address bar must be present, and the URL to refresh must be there...
But it is the most reliable way I found, I tried:
#^x:: ControlSend ahk_parent, {F5}, Microsoft Internet Explorer
but it wasn't working each time. Working better with a minimized window, curiously...