Keeping in mind that the first part of the URL is either the machine name, a qualified internet address, or an IP address you cannot use "docuware.read" unless you install platform Read only on a machine called "docuware.read". This is because both the full licensed version and the read only version reside on the same machine.
Better would be to use some form of IIS redirection. So the user will enter http://machine name/DWRead or something like that, and IIS can then redirect to the correct read only URL.
https://docs.microsoft.com/en-us/iis/configuration/system.webserver/httpredirect/
Using redirect you do not interfere with DocuWare's internal structures.
Phil Robson
Senior Director Support Americas