Hi,
Thanks for the answer. However, maybe I was not clear enough.
My target is to make, lets say, page-template-doc-preview my default page template, instead of page-template-default.
In my case, I dont need to create a single-wpdmpro.php file, because the main page structure is already fit for me. I just need to set page-template-doc-preview as my default page template.
best,
alan