.htaccess - code for domain masking?

[Nova]

I'd like to be able to implement domain forwarding masking from within the .htaccess file. Is there any code I can add that would accomplish this? Thanks. This is what is already in the file:

RewriteEngine on

IndexIgnore .htaccess */.??* *~ *# */HEADER* */README* */_vti*

<Limit GET POST>
order deny,allow
deny from all
allow from all
</Limit>
<Limit PUT DELETE>
order deny,allow
deny from all
</Limit>
AuthName www.example.com

RewriteCond %{HTTP_HOST} ^.*$
RewriteRule ^/?$ http://www.example2.com/?criterion=example.com [R=301,L]