How Complex to add your own trailer in movie?

[Graffix]

I was wondering. I want to add my own little trailer, like the THX and Dolby Digital trailers. I'm sure its possible. But how complex would it be?

[LT. Columbo]

i do something like that to a lot of my dvd's that i create.

i simply convert the main title and my "trailer" as 2 seperate mpeg-2 dvd compliant files with tmpgenc plus and author them in tmpgenc dvd author, AS 1 FILE. they will play back as if they were joined--very nice, very simple