Article by (I don't know who) at the iisadmin site.
http://www.iisadmin.co.uk/?p=326
You'll need the Application Request Routing package from here: http://www.iis.net/download/ApplicationRequestRouting
This is another way for integration IIS and Tomcat.
Related: http://my.opera.com/AxxL/blog/2009/01/28/setting-up-64-bit-tomcat-6-on-iis7