Create the following folders on the root of the C drive:
"C:\Mount\BootWim"

Copy "\\az-dwm-web01\OSD\AutoUnattend\USB_Stick_Creator\Boot_WIMs" to "C:\Temp"

Copy "\\az-dwm-web01\OSD\AutoUnattend\USB_Stick_Creator\Drivers\Dell" to "C:\Temp\Boot_WIMs\Drivers"

Open a CMD prompt as Administrator

Use the following DISM commands to show the index of a boot.wim:
DISM /Get-WimInfo /WimFile:"C:\Temp\Boot_WIMs\boot_it-IT.wim"

Use the following DISM commands to mount the boot.wim:
DISM /Mount-Wim /WimFile:"C:\Temp\Boot_WIMs\boot_it-IT.wim" /Index:2 /MountDir:C:\Mount\BootWIM

Use the following DISM command to add the driver:
DISM /Image:C:\Mount\BootWIM /Add-Driver /Driver:"C:\Temp\Boot_WIMs\Drivers" /recurse

Use the following DISM command to unmount the boot.wim:
DISM /Unmount-Wim /MountDir:C:\Mount\BootWIM /Commit