extra links with xmlsitemap

When we create subdomain pages / subdomain landing page with the module, and we need to generate the xmlsitemap for the google /yahoo.

The sitemap which is being generated is for whole site. There should be subdomain pages should be excluded otherwise the google will through the error in sitemap.

I'm not sure, If this request should be posted in xmlsitemap or subdomain. But thought that subdomain knowledge is more here, so posting this thread here.