I don't know if this is possible with expressions at all, but here goes:
I'd like to link a group of time remap keys to markers on that same layer. So the red keys should move when I move the red marker, the green keys with the green marker, yellow with yellow, etc. In this case those are time remap keys on a precomp, and the key pairs define time ranges of that precomp (the red keys cover frame 0-100 for the object entering the frame, the green keys cover frames 100-50 for the object spinning around, etc). Since I need several copies of the precomp in my clip, and pauses between the time ranges differ, having them move with markers would make it very easy to change.
Can this be done with expressions?