Add user to a group

I am using csvde to import loads of users to active directory. I am using a csv with all the entries I need and can sucessfully add a test user.  The issue I have is the group membership - When I add a column called "memberOf" and then add the line for each user for the path of the icons to "CN=IC_SC_Icons,OU=Icon Distribution Groups,OU=Company,DC=co,DC=uk"

When I run CSVDE to import the csv I get an error Unwilling to perform.  Access to the attribute is not permitted because the attribute is owned by the SAM.  

How Can I add a group to the user using a csv list with csvde. Bear in mind each user will have a different group.  

I have attached an example of the CSV I am using

Many thanks




TestImport.xls