Create custom host file and install

Hi all, 

I'm having issues completing a custom host for our business. I have been able to do the customise and download the installer, but can't seem to workout how to get it to auto assign to our corporate account. I have downloaded the autoassign exe and tried to add the commands behind it but still can't seem to get it to work.

I have tried diffent things and continue to read knowledge base articles but still does show as assigned

any help would be greatly appreciated