I don't think you can do that right now. If you don't have an resolvable DNS name for the vCenter you can can try to add it the hosts file on your Environment ActiveGate (or Dynatrace Cluster node, depending from where the connection is initiated) and supplying the DNS name in vCenter. I think this will do the trick.
@Henk S. I would recommend you change the configuration at the VMWare part of the settings. You would just need to supply the fully qualified name to the host, much like you did with the IP, toss in the password and it should update the naming convention.