Hi,
I know this is not a silverstripe-specific issue, but someone may have struck this.

I am wanting to make a modification to the mod_rewrite rules in the .htaccess file to prevent re-write engine from operating inside a sub-directory.

The situation is that the silverstripe content is in my base directory, and I am operating phplist (http://phplist.com) from a sub-directory.
The phplist application generally calls new pages in it's own directory with the directory name only, not a specific file name. (e.g. http;//<domain>/phplist//admin/?page=list )
These calls are unfortunately captured by the mod_rewite & a silverstripe page not found is returned.

I have tried various RewriteCond statements such as:
RewriteCond {REQUEST_URI} !^phplist
but don't seem to be able to get it right.