in subdomain multisite installation, there is a need to create unusual redirect. I need to configure subdomain xxx.siteaddress.com, which redirects to siteaddress.com/contentsite and xxx.siteaddress.com needs to stay visible in address bar. This is internal configuration (subdomain to page in wordpress).
Could you please give a hint where this configuration could be done, without harming generic multisite configuration? (htaccess?)