rewrite rule only if file not in folder, possible?

[Cups]

Say I already have a list of other files and folders in the root directory of my site:

mysite/staticpage1.php 
mysite/staticpage2.php
mysite/folder1
mysite/folder2
... etc

And I now want to add a mod_rewrite rule that serves the content of requests like

mysite/dynamicpage1.php

From

/pages/index.php

and yet I do not want to interfere with the existing pages and folders, nor do I want to change file extensions.

Is there a way of using mod_rewrite, or similar so that it (pseudo)

if file is found, go there
if folder is found, go there
else get content of /pages/index.php?<URL>

I would normally just create a folder and send the links to, and serve the content, from that folder - so have not really come across this challenge before.

Is it possible to do this without invoking and handling a 404?

[Raffles]

I think this could work:

RewriteEngine on
RewriteCond %{SCRIPT_FILENAME} !-f
RewriteCond %{SCRIPT_FILENAME} !-d
RewriteRule ^(.+)$ index.php?$1 [L]

The -f switch means "not files" and -d means "not dirs". So if those are both satisfied, the RewriteRule below is applied.

[Cups]

Thanks Raffles, I have tried that locally and it seems to work as expected.

Nice one.

(Fond memories of Cambridge, we lived ~there for ~8 yrs)