Any advice on how to copy lists with lookups to a different site collection with powershell? Of Course, I want the Lookup columns to point correctly within the new site collection. Keep running into a crossweb error after updating the site column List, WebId, and SourceId fields for the lookup.
Please checkout this informative article which seems close to your asked concern and should be helpful to work around your situation – http://sharepointquicksolutions.blogspot.in/2012/07/migrating-list-which-contains-lookup.html
In case you wish to automate the process, Lepide SharePoint migrator should also be an ideal approach for you. More information can be obtained at http://www.lepide.com/lepidemigratordocuments/