combine generated sitemap with sitemap of non-wordpress pages

I would love to know if it is possible to combine this generated sitmap with a sitemap generated from crawling the non-wordpress pages on my website – like made from freesitemapgenerator.com. All pages are on the same domain, it’s just I have about 1000 pages of boring static content (competition results that are generated from the scoring software in html format) that are not part of wordpress. I can’t add those one by one. Ideally, I could put that sitemap somewhere and your sitemap generator would include it into the main sitemap.

Possible?

Anyone else need that feature?

http://wordpress.org/extend/plugins/google-sitemap-generator/