Hello,
the crawler that is built into sitemap generator includes all pages in sitemap, but there must be a way to *find* those pages.
It's NOT necessary for those pages to be visited by other users.
As I see from your pages structure, the only issue is that your "next page" links are in javascript, like:
<a href="javascript:loadList('',%202);">
so they cannot be crawled. You should change those link to html URLs, like:
<a href="news.php?ACTION=filter&RL_PAGE=3&RL_LETTER=&SORT_COLUMN=date&SORT_DIR=desc&SHOW_CAT=">
and that will resolve the issue.