Ok, for hostname you could use any random (but non-reserved) name as subdomain - such as randomone.ew3d.com. You could then create a virtual server for ew3d.com and freely create as many subdomains on as many virtual servers as you like. I feel this would be the best way.
For example, I have a white label domain Indiax.com. I use vps01.indiax.com as hostname for one server, vps02.indiax.com as hostname for another sever and so on and so forth. This does not prevent me from showing a website on www.indiax.com or, say, qr.indiax.com or running a SaaS on crm.indiax.com (under which can be created potentially unlimited subdomains under the subdomain crm.indax.com). I mention real examples of domain names in order to enable you and others to use DNS lookup tools on the domains that I have mentioned to see how they have been configured. It is possible to plan a deep and potentially unlimited hierarchy of subdomains under a single domain which spans multiple servers.
If you want to chat with me about this, see: