Since you cannot "reference" an account from another machine in the ACLs of Windows in workgroups, you need to use a service account on the QVS services that has an equal account on the "DataCenter" service. A local account, that is.
Basically, you need to create the local user "QVServices" on the "DataCenter" machine, and give it the same password as it has on the server where the QVS services reside.
Make sure to reference the accounts as only ".\QVServices" when setting service account details and such in configuration, do not use "servername\QVServices". Remember - you're not in a AD domain.