AS 3.0 Help with crazy timeline LOL :)

Here’s another one. I have a movie that is 2:59 seconds long. Above the movie, I have a Text that I converted to a Movie clip. Inside that movie clip I made a fade effect. So the text is invisible at first and then fades to where you can read it. Just set the alpha to 0 on the first frame. F6 out 24 frames and set that alpha to 100%. Creat Motion tween. Real easy.
This is what I am trying to do. I want this little motion tween of mine to start when the video hits 2 min 50 seconds. That way the text will start from invisible to visble when the movie ends. But, I want it to start at 2 min 50 seconds into the video.
Now, this may sound stupid, but I tried to go out in the timeline to where this should occur. I am running at 24 FPS. So, at 2 min 50 sec, that would be 170 seconds. Take 170x24FPS and that is where your video would start. On that frame. Which according to my mathmatical brain, that would be frame number: 4080! LOL. I actually tried to go out that far, but it caps out around 3,00 frames LOL. There must be an easier way to run this Motion Tween there Action Script :).
I am using Adobe Flash CS3, Action Script 3.0. Any solutions will be greatly appreciated! Thanks all!

Semper Fi