Pointer-events is a Mozilla hack and where it has been implemented in Webkit browsers, you can’t expect to see it in IE browsers for another million years.
There is however a solution I found:
Forwarding Mouse Events Through Layers
This uses a plugin that uses some not well known/understood properties of Javascript to take the mouse event and send it to another element.
There is also another Javascript solution here.
Update for October 2013: apparently it’s coming to IE in v11. Source. Thanks Tim.