I am trying to migrate data from CRM on premise to CRM online.
I need to set the Ownerid value, but LCS Data Loader only seems to allow a GUID to be provided, not a lookup to the target user.
I also need to refer to users where referenced by loads of other lookups, e.g. on Activities.
The GUIDs for users will be different in CRM Online since users are auto-created by Office 365 - you can't preset the GUID to be the same as on premise.
So we need to be able to perform a lookup to the CRM Online user somehow, but I can't see how to do that in LCS Data Loader.
If this cannot be done, then there is a huge data transformation task to modify all data prior to import to substitute the old systemuserid values with the CRM Online equivalent. That is a major piece of work, easy to miss all the lookups there are in CRM to this core entity.