Coursepress: How to add course name to invitation e-mail? (Simplylearn)

On default mode in coursepress, the name of the course is not added in the heading of the invitation e-mail one can send to potential course users. Knowing a lot of e-mails easily looks like spam to customers, I want them to know what this is all about just from the heading, without having to open the e-mail to read the course name.

I tried to steal the code («%2$s») from the body of the e-mail and put it into the header, but it just showed up as code.

How can the name of the name of the course to the header of the course invitation e-mail?