The File Switcher plugin may (or may not) suit your needs. It presents a sortable list, and has partial-title quick-search...

You can find it here: [Directory for Notepad++ plugins][1]

Here is a summary from the Plugins page:
"... a little plugin that switches between files, by entering any part of the filename. It's handy if you don't like taking your hands off the keyboard to switch files. Formerly known as Keyboard File Switcher." [1]: http://sourceforge.net/apps/mediawiki/notepad-plus/index.php?title=Plugin_Central

The File Switcher plugin may (or may not) suit your needs. It presents a sortable list, and has partial-title quick-search...

You can find it here: Directory for Notepad++ plugins

Here is a summary from the Plugins page:
"... a little plugin that switches between files, by entering any part of the filename. It's handy if you don't like taking your hands off the keyboard to switch files. Formerly known as Keyboard File Switcher."