Resolved this one:
1. Using UDI add domain and OUs
2.TS variable Options section = OSDDomainOUName
condition = equals
Value = OU=COMPUTERS,OU=IT SERVICES,OU=CLIENT MANAGEMENT,DC=mydomain,DC=LOCAL
3. on the same Step TS Variable = OSDComputerName Value = LAPW7T-%SerialNumber%
4. Make sure and put this step or group after Apply Network Settings