I have played around and found a way to download actual CAB and MSU files and integrate them into the image, using the suggested DISM technique.
Head to GOOGLE and search for WSUS Offline. This is a great peace of software that lets you download update files for specific OS. The file are not express in CAB and MSU format. Use the option in WSUS Offline to copy downloaded files to let’s say C:Updates Follow the instructions in this article and when you get to the point that you need to type in the command to inject the updates to the Image use the following two commands:
Start /w for /R C:Updates %f in (*.cab) do DISM /image:C:Mount /add-package /packagepath:”%f”
Start /w for /R C:Updates %f in (*.msu) do DISM /image:C:Mount /add-package /packagepath:”%f”