I had this very same problem, so curious to hear another answer/opinion on this - I was on the phone with HP as we tried to work through this but couldn't get them to sycnhronize and authenticate by LDAP.
Here's what I tried:
Need to set up an ldap synch for hosts. Which means you need a filter condition like this:
(&(objectclass=computer)(dNSHostName=*)(accountExpires>=now))
because workstations look different in LDAP. Then I created a policy using eap-peap/mschapv2. Because hosts come across as host/<hostname.domain.net> or whatever your domain is - and yes the slash is the other way from domain\user, so unclear as whether the prefix filters work properly - and you need a suffix in a service to use the policy.
For whatever reason the above, which looks like it should work, did not authenticate. In PCM its all MS NPS, so it reads AD fine for users and workstations. But in LDAP the credentials work differently for hosts. Maybe I got the certificate type wrong.
I could only get the imc computer user to work. I really just need to make sure the trusted machines do authenticate, so it can connect users to domain controllers. And I can remote into them. You may have additional requirements.
But sounds like you already tried this:
Set up the computer account. Create a PEAP service for it, point to an EAP-PEAP policy.
Then configure the virtual computer in IMC User>User Access Policy >Service Parameters> System Settings>Domain Controller-Assisted PEAP Authentication.
The workstations show up in online users as Account Name: computer, Login Name: <hostname>, Username: computer, so you can at least see them as separate line items and track them. But not as separate "accounts"
And only one domain is supported...