Yes, but we can't retrieve the y offset. To do that, we have to add for ex Y offset + 2 on each loop.
But we can't retrieve the current Y offset.
I'm not sure what you exactly mean by that. You don't have to use loops for this either.
Try this for a basic example:
http://dl.dropbox.com/u/2306601/tbgoff.cap
The offset is controlled with the private variables of the Tiled Background object.
Oh, and in case you get an error while trying to open this cap, I'm afraid you'll need a newer version of Construct. In that case just grab 0.99.84.