That requires a tool called USB Gecko. If you have ever hacked a .rom you would know to search for greater then, less then, equal, this is what the USB Gecko does. Unlike .rom hacking they're 100's of thousands values. Even after finding the value you want you need to insert the proper code type.
Here's a link to some tutorials I made on it:
http://www.youtube.com/playlist?list=PL5C65F1C1F55B1913Note that USB Gecko's are really rare now, if you find a site that still has some in stock you're lucky.