Trailing Slash problem

[plough]

Hi folks,

I've got I question related to xcandyman's and I have looked everywhere to find an answer.
Maybe you can help?!

This is (a part of) my .htaccess:

RewriteEngine on
RewriteCond %{REQUEST_URI} (.*)\/$
RewriteRule (.*)\/$ /index.php?page=$1

It works fine when I use the trailing slash:
www.host.com/test/

but it does not without the slash.
I have found out how to add the slash automatically, if the 'dynamic' directories are in in subdirectory:
www.host.com/dir/test(/)

How can I have the slash added, if die dynamic directory is behind the host?

And one more question - sorry ;)

How can I prevent the server from performing the Rewrite rule, if I have got a really existing directory with an index.html in it (e. g. www.host.com/html/testdir).

Thank your very, very much in advance
plough