Probably not with VSEs automatic updates.
But you should be able to achieve it by setting up scheduled task on each computer to run the ****xdat.exe DAT updater.
Just to elaborate on the procedure...
1. Every day download the ****xdat.exe (where **** is the DAT version) from the McAfee website and transfer it to a usb stick
2. Take your usb stick to the isolated network and copy it to a network share on a server or PC
3. Rename it to todaysDAT.exe
4. Each computer has a scheduled task to run todaysDAT.exe from the network share
Really what i need the content of sitelists.xml. I cant edit it because locked by mcafee services. I dont know what i have to put or write into that file manually. Can anyone give an example for "local content" or "UNC path"?
I think you can do it that way but it's slightly more complicated
The McAfee automatic update process that uses the sitelists.xml isn't expecting a single file to perform the update.
Basically you will need to download the contents of this folder to your usb stick every day and recreate it on the network share on your isolated network.
You can then edit the sitelist.xml via the VSE console.
Tools - > Edit AutoUpdate Repository list
create a new UNC repository and point it at your network share and move it to the top of the list