Hi, Chad
I'm guessing you're trying to set up an Event for that? If so, you're right: we don't currently have a variable that can be used for the follow-up date. What I'll do is write up a feature request for this.
For the time being, you could create a Canned Reply that can be used when the Reply with Follow Up reply option is used, insert that new Canned Reply, and then just manually fill in the date for the work to begin.
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com