Download only missing updates for current system

[macgyver2004]

Is there a way to make WSUS Offline download only missing updates for current system?
I've made custom Windows 7 instalation DVD which has many updates integrated.
I would like to automate downloading and instaling updates with WSUS Offline, but I dont need download all the updates every time.

I was thinking about listing installed updates and adding them to exclusion list.
How it could be done?

[Denniss]

Add them to the two exclusion lists for Win7, ensure they are entered properly:
ExcludeList-w61-x86.txt
ExcludeList-w61-x64.txt

You may also want to untick the uption to include Servicepacks in the Update Generator. If you already included Dotnet 3.5/4.x in your installation media you may want to remove those from \static\StaticDownloadLinks-dotnet.txt

BTW WOU downloads updates only once and keeps them until marked as replaced.