User Profile Wizard, that lets you convert a local windows or domain profile to a domain windows profile. So join a PC to the domain, login as the domain user, restart, login as and admin account, install User Profile Wizard and run it, select the source account, then the domain account, let it run, restart and login as the domain account. You are now using the source account as the domain account. The only thing that doesn’t come across is the credentials in Credentials Manager, eg stored cloud credentials such as 365 login etc.