HSDL update location in position table

I am trying to use HSDL to update the location of certain positions. I generate the spreadsheet and it asks me for a Location Code. I supply the Location Code as per the Positions table extract and when I upload I get the error "You need to enter a valid value for the LocationId attribute. The current values are ….". I get this error if I use Location Code and if I use Location ID in the Location Code column. What am I supposed to put in the Location Code column to get this to work?

Thank you