Need help with filmstrip effect

[Animated]

So, the thing is that I want to show a filmstrip that is rolling vertically on the screen, and in it's blank spots I want to include videoclips. What's the easiest way to make the videoclips keep up with the moving filmstrip? I guess that parenting the clips to the strip would work fine, but when I use the Offset effect on the strip, the clips don't move along with it. It seems like there's an easy solution for this, so... help would be much appreciated

[Eake4]

1. Find an image of the film strip
2. Create a new composition with the dimension of the film strip
3. put your video file or whatever you want on the blank spaces in after effects with position tool (you might want to use mask tool to fit it in exactly)
4. Pre-compose the film strip together all the layers you put on the blank spaces and change settings of video project back to what your working with (probably 720p since it's you)
5. use the position tool to move the pre-composed layer AKROSS the project
6. Enjoy

additional note: you might want to turn on motion blur to make it look nicer

Shortcuts mentioned:
Precompose: (crtl+shift+c)
Position: p
Setting composition settings (right click, change comp settings)
Mask tool: g

[Animated]

WORKS LIKE A CHARM

[FarmXD]

5. use the position tool to move the pre-composed layer AKROSS the project

You killed me. I just....died xD