Send Certificate request with Client information machine name

I have set up a server with a client certificate with web enrolment on Server 2012 R2 Standard, IIS, which is working with AD Windows computers across the web from our DMZ. For non-domain computers I maked template with must be taken by request Subject field. I planningto send on CA a request with the name of client local machine in certificate attribute as subject (CN=....), but I have a problem how to do it without manual enter this attribute.How can I change web enrollment .asp pages (maybe certrqbi.asp) to do it. Because on CA mmc from failed requests I viewed my request have Client information attribute with User and Machine (szOID_REQUEST_CLIENT_INFO).