ActionScript :: Timeline Control - How To Show Certain Words In Frames

I'm dynamically loading a file that will indicate when to show certain words at certain frames. However, I'm having trouble with the concept of timeline control from ActionScript (I'm building everything programmatically in Flash Builder). Let's say my tuples has frame and word:
5, "duck"
13, "cow"
22, "pig"

There is a sprite associated with each. What I would like to do is something like the following:
for (frame in timeline) { //should iterate from frame 0-22 (last frame in list)
if (frame in list) {
list[frame].alpha = 0;
}}

I already know that my display of sprites works and whatnot, I'm just confused on how to play through the timeline in this kind of way, or if it's possible to dynamically do this. Related, can I control how fast the timeline plays? To give a more thorough explanation, I'm looking to visualize word appearances over time in a text. So "duck" may appear as the 5th word in a corpus, "cow" as the 13th word, etc. My list contains tuples of word positions (unique) and the word that appears at that position.

I have a small selection of words that I'm interested in from the corpus, so not every position is represented. I would like to be able to have a SWF movies that essentially starts at the beginning of the corpus, go through my word list in order of appearance in the corpus, and then display the word (and have it fade out). So, if there's a word at position 5 and 10, then should appear in much more rapid succession than if there's a word at position 15, and the next one doesn't appear until 50. Basically, I would like to keep that temporal component.