Well I’ve not read that work by CSL, but I’ve read a number of others, and the description of Surprised by Joy also talk of a journey from atheism to Christianity. Again, I’m missing the focus on a certain church or denomination in any description of this book that I can find.
My own faith has nothing to do with any church or denomination, and I never found faith until I left the Presbyterian church in fact. To me, the “church” Jesus refers to is the universe of true believers, and frankly, I think only a few of them reside in mainstream churches.
It's obvious you've not read it; that's why I recommended you do so. Your post to which I first responded said nothing about denominations; it simply accused Hahn of making a cottage industry of his conversion, to which I stated, quite accurately that the very same could be said of Lewis.
Lewis, in the very first paragraph of his preface to the book discusses, "my conversion," and he continues to refer to it as such throughout the book...indeed, the book is his spiritual autobiography. Which only reinforces my point: While Lewis is best and most widely known for his apologetics, had he remained unconverted, he would most likely have been remembered as an obscure academic, hence my contention that you could say his conversion became his "cottage industry," or at least the foundation upon which it was built.
And no, he did not jump from atheism to Christianity. He dabbled with various sorts of paganism and a general theism in between. They may not be "denominations" in a rigid sense, but they are (to include atheism) systems of faith and Lewis very positively saw his shifting views as "conversions" in much the same way Hahn regards his.