change number of available site pages displayed

We are building a site which could end up with over 100 pages - currently all at the same level below root for the reason given below - and the client needs to access these to maintain content. The client has poor PC skills beyond basic PC use and typing and may not be able to find particular pages to edit easily using the "search" bar.

The basic PowerCMS admin interface shows just 6 big blue tabs with different pages - e.g. "aboutus.php". How can I list all the available pages - and is there a smart way to produce a page listing that looks like the standard microsoft interface when folders are listed and then expand them to show their content. This would be a very useful feature for larger sites as the pages could then be ordered at different levels within the site to relate precisely to the main menu bar on the index page. The client could understand this.

The site we are building is for the British Legion - i.e. serving and retired folk from the armed services at www.bedwynlegion.org.uk