The record that I want to eventually delete is in a subdomain, and the syntax calls for the zone only. So our reverse zone is .yyy.zzz.in-addr.arpa, with subdomains for each subnet beneath it. So the xxx subnet would be a subdomain beneath the .xxx.yyy zone.
If I issue an dnscmd /RecordDelete .xxx.yyy.zzz.in-addr.arpa. computername PTR 10.x.x.x
I get an error: Command failed: DNS_ERROR_ZONE_DOES_NOT_EXIST 9601 (00002581)
I can delete a record from the actual yyy.zzz zone, but not the subdomain.