Hey Michelle,
There is a list of all the currently available replacement variables on the programs messaging screen, in the help popup above the body input box. At the moment it there are only three, %userfullname% - the full name of the email recipient, %programfullname% - the full name of the program, and %setlabel% - the name of the course set.
There is an existing enhancement request to add %username% - the user name of the email recipient, %enrollmentmethod% - how the user got enrolled to the program (audience, position etc) , %completiondate% - the date the user completed the program, %managername% - the name of the recipients manager, %manageremail% - the email of the recipients manager. If you have any other replacement variables that you think would be good let me know and I'll add them to the enhancement request.
we are hoping to have some time to work on some of the minor enhancements like this soon now that we have gathered some feedback from community about which ones are more important. I'm hoping this one has made the list but I haven't seen the results yet.
Cheers,
David