Removing apps from 'Mobile Applications' that aren't in iTunes?

Removing apps from 'Mobile Applications' that aren't in iTunes?

I'm running iTunes on Windows 7, and at some point (or rather, at multiple
points) I must have accidentally pressed the 'Cancel' button when it asks
if I want to remove the app from my hard drive when deleting it in iTunes
The net result is that I have 503 apps in iTunes, and 598 apps in my
'Mobile Applications' folder.
Is there anyway I can tidy these up? ie some way within iTunes that will
clear the Mobile Applications folder of any apps that aren't in my iTunes
liberary?
Thanks