So to begin with I have a custom url rewrite that sends a request variable to a php script
Rewrite rule is below:
RewriteRule ^([\\w\\/-]+)(\\?.*)?$
This is supposed to redirect /slug-text to /slug-text.html
RedirectMatch ^/([\w-]+)/?$ http://domein.com/$1.html
This is in the case when slug-text is only letters, digits, – and _. Rewrite slug-text.html to a php file and pass the slug as a param:
RewriteRule ^([\w-]+)\.html$ test/index.php?slug=$1 [R,L]
If you have both line in your .htaccess the first one will do the redirects from the legacy URLs to the new ones and the second one will process the request.