[MeTh0Dz]

Couldn't you just hook explorer or whatever program it is and then keep track of when there are right clicks and then open up your menu.

Or you could have a program that watches all currently active programs and it notifies it self when explorer or whatever opens up. Then it just keeps track of right clicks in a certain window, or 'x, y' plane. Which you could get from getting the foreground window, or by using system metrics.