You can use this soft : http://www.digitallis.co.uk/pc/ShortPopUp/index.html
it is a exe (not loaded in systray, just executed when needed !) that fire a popup on custom's directory, folow window's links, preview html and docs....
Choose a gesture and link it to this exe, done.
Note that this exe takes in parameter the target directory to popup, so you can define multiple gesture to have multiple popups.
Have fun !