Can't find the words to Express myself, Nestled parenthesis?

Question

Hi,
I have a project I am supposed to turn over to other people so they can "easily edit" and produce the same thing over and over. that would be too simple, so I decided to put as much of the stuff they would need to adjust into a comp "configuration"
this is the expression I used to change the text at any given time. I like this expression because it's easier to work with than source and lets you move markers over lots of layers without having to twirl down each layer to read or move keyframes:
comp("configuration").layer("EDIT-TOP-TEXT-PANEL1").marker.nearestKey(time).comment;
the problem I am having is that it chooses the nearest marker, so you have to guess/tweak till you find the middle. Instead I want to use the last marker until I reach the next
thisLayer.marker.key(thisLayer.marker.numKeys).time
when I try
comp("configuration").layer("EDIT-TOP-TEXT-PANEL1").marker.key(comp("configuration").layer ("EDIT-TOP-TEXT-PANEL1").(numKeys).time.comment)
I've broken the expression, I've actually tried to reference the external layer a few ways but seem to break everything when I leave tried and true.
(thanks Mylennium for the pointer to the expression)
BTW, those learning expressions, should check out this page, it's got some nice reference and examples.
http://www.jjgifford.com/expressions/basics/index.html

Answer 1

This might be what you're looking for:
L = comp("configuration").layer("EDIT-TOP-TEXT-PANEL1");
n = 0;
if (L.marker.numKeys > 0){
  n = L.marker.nearestKey(time).index;
  if (L.marker.key(n).time > time) n--
(n > 0) ? L.marker.key(n).comment : ""
It should display the comment of the most-recent previous marker (or nothing, if there isn't one)
Dan