>> Forward a blog to another one

I create a blog via Network / network is a multisite-domain with witch I create subdomain site,
anewaddress.site.com for example, I would like a shortcut like "ana.site.com" forward to the initial address
Q. How can I do to put in ana.site.com root folder a .htaccess link to anewaddress.site.com ?
And where is root folder of subdomain site ?
Thank you