This allows you to rename the WORKGROUP name to something else:
VBscript
On error resume next
Set objShell = CreateObject(“WScript.Shell”)
objShell.Run “cmd /c C:\path\NetDom_NT.exe MEMBER \\%computername% /JOINWorkgroup New_Name_Here”, 0, True
WScript.Quit(0)
Shell
c:\path\NetDom_NT.exe MEMBER \\%computername% /JOINWorkgroup New_Name_Here
Notes
Join Computer to Domain
NETDOM /Domain:MYDOMAIN /user:adminuser /password:apassword MEMBER
MYCOMPUTER /JOINDOMAIN