There is no fundamental difference in returning a mark for a student against an EX- class code.
In order to return to these EX- classes you will need to hold the External Marks Return role on the class.
These class-codes may be "owned" by organisational units outside of your own, in this case you will not be able to self-assign the Electronic Marks Return role yourself via PEGASUS (see Add Formal Staff Roles to a Class)
If the EX- class-cdoe is owned by organisational unit outside of your own, you should contact your relevant Student Business team and ask them to give you the Electronics Mark Returner role on the class code.
Myplace Support cannot do this.
Once you hold the Electronic Marks Return role on the EX- class code the Marks Return process for external study classcodes is no different from any other class offered by the University.
EX- class codes may not have a corresponding Myplace site.