One.com hosting htaccess help.

Hi to all,

I help a friend of mine to install a WordPress multisite on one.com.
Everything went fine without any problem. Installed a theme, started to add content and etc.

In one.com the hosting is bound to a domain i.e. domain.com.
My friend want that in one of the multsites i.e. domain.com/path wants to use another top level domain ie. path.com.
The path.com domain just have a domain control panel (not in one.com) and there I did change aname/cname to actually point to domain.com

Then I thought that the simplest that I could do was actually just to make a rewrite rule in htaccess, but it doesn’t seem to work.

ReWriteCond %{HTTP_HOST} path.com
ReWriteCond %{REQUEST_URI} !path/
ReWriteRule ^(.*)$ path/$1 [L]

I talked with one.com support but they are saying that is not possible to something like that, but I wanted anyway to ask if someone found a way around this or has any other solution.

Thx in advance