Navarro:
I discussed this with an engineer directly involved with scripting in AE. Unfortunately, there is no scripting support for Comp-time markers (which would be a way to give you what you want) at this point. He took note and a feature request was filed.
In case you ever find it useful (I know I would), at the redefinery web site there is a script which will copy layer markers to another layer:
<http://www.redefinery.com/ae/view.php?item=rd_CopyMarkers>
Best,
Adolfo Rozenfeld - Adobe