Sitemap Generator Forum

I have this kind of url - [ External links are visible to forum administrators only ] with the number after the "-" ranging anywhere from 1 - 20.

Actually the correct url for that product is -
[ External links are visible to forum administrators only ] the other url is a duplicate.

How can I exclude the url's with the appended "-#'s"?

You can add this in Exclude URLs setting:
.*-\d+/$