This file is located in your templates folder under the SetupCast data:
If you want to change the default content of the template you can copy the RTF file (you should save it as a new name) and modify to suit your needs.
Hint: Use the Windows WordPad program to modify the RTF file - NOT Microsoft Word.
The default RTF template looks like this:
When displayed in the Enhanced Web Update Client (with merged data) it looks like this:
(sample screen)
If you modify your copy of the template, the next step is to use the Merge Template selection for the RTF file in your Project Settings to tell SetupCast to use your (modified) file for the merge as shown here:
The template system is a very powerful feature of SetupCast and is covered in the main help file.