First step, enable webdav in plone. Go to the zinstance/etc/zope.conf file and unremark the webdav part.
# # valid keys are "address" and "force-connection-close"
And restart your zope. That ought to make it listen to port 1980 on localhost for webdav connection.
Then go to your apache web root folder and add a folder with the same name of your plone instance. Inside there put a .htaccess file like this:
RewriteRule ^($|.*) http://localhost:1980/dev/$1 [L,P]
And that will redirect any access to your folder to the proper port (Note: because you can't use VirtualHostMonster for webdav, it has to be in the same folder as your plone instance. You can put the redirect to your plone instance in a different folder and redirect it from there with VirtualHostMonster).
Okay.. Once that is done you should be able to access it using a webdav client. It has to be a webdav client, not your browser because your browser will not know how to handle webdav. Ok.. so for the webdav client? For ubuntu you can try here:
http://sysblogd.wordpress.com/2007/09/09/ubuntu-mounting-remote-filesystem-using-davfs2-fuse/ . Then you can use it just like a normal folder. Cool.
Oh.. for more reference go to: