By popular request, I am posting these instructions for adding a video before the main menu plays.
Video before Menu...
PgcEdit has a menu item that will import a title and make it play first. http://www.videohelp.com/~r0lZ/pgcedit/index.html
You still use Premiere Elements to create your projects.
You need two Premiere Elements projects that you have burned to folder. One is the main DVD and the other is the one you want for first play before the menu.
What you have to do in PgcEdit is open the main DVD Video_TS folder created by Premiere Elements. Next you select Title - Import First Play (startup) Clip. After accepting the default prompts, you navigate to the other VIDEO_TS folder and select an IFO file that has the clip you want for first play.
Next you'll probably want to limit user operations on the first play item, so you double-click on the first item in the list that reads "VMG, First-Play PGC...". That opens up a dialog where you can select which user operations you want to prohibit.
Once done with that, you can do a File - Save DVD.
Use a third-party app to burn the VIDEO_TS folder as a DVD-VIDEO.