# include file
serveralias www.domainA.com
serveralias www.domainB.com

# "catch-all" vhost
<virtualhost x.x.x.x:80>
 servername catch-all
 include /path/to/include/fil

 rewriteengine on
 rewritecond %{HTTP_HOST} ^(.*?)
 
 # %1 is domain name from above rewritecond
 # $1 is domain.com/(.*)
 rewriterule ^/(.*) http://www.redirectedhere.com/%1/$1 [R,L]
</virtualhost>