Not sure I get what you want the page to look like. Do you want all the pages of one comic, no matter when you uploaded them, to show on the same page, as one big scroll instead of the several scrolls you got now?
If so, the easiest way is to give them all filenames with the same date.
Comicpress automatically creates a new post for each page, but only one comic post per day. So if you upload more than one with the same date, you'll get multiple-page posts.
Now, if you upload new pages with the same date as last week's pages, in theory those pages should just add to last week's post.
You won't get a new post, though, and no rss notification for regular readers.
There may be a way to tweak CP into displaying a post at the bottom of another post instead of a new page, but that's some major php mojo. I'd recommend asking Frumph at http://www.comicpress.net/forum
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