Q: Can I download/install additional patches?
A: Yes, you can adjust how the download and update scripts behave by excluding or adding patches from download or installation. For adding updates proceed as follows:
1. Adding updates to download routines
For adding an update to be downloaded, insert its download URL into the matching "StaticDownloadLinks-<platform>[-architecture>]-<language>.txt file, found in the "...\static\custom" directory. Please don't forget a trailing.
2. Adding updates to installation routines
Add an update to installation by inserting its knowledge base ID (KBxxxxxx or simply xxxxxx) into the matching "StaticUpdateIds-<platform>[-<architecture>].txt file (directory "...\client\static\custom"). Please don't forget a trailing.
based from the faq within Wsus offline update