Use of subdomains - using webrules to point to single directory (rather then serving the site!!)

Hi all,

I added a subdomain to my account but all it does is point to the webroot i.e. I can access the modx site from this. I want to be able to only access the assets directory from this subdomain.

Is this possible with nginx webrules. Can you user server { location { ??

Obviously I want the assets directory to still be accessible from the full domain.

Thanks in advance.

modx cloud 2.3.1