Thanks,
a rule for this will be very easy to create in the next version with support for "placeholders".
Meanwhile, we can get result also with current version:
From URL: ^/[0-9]{1,2}\.[0-9]{1,2}$
With this regexp you will match all "chapters" in the form /xx.xx. Now we should build the destination. We can use the preg_match macro, but is available only for Enterprise version:
To URL: http://{siteurl}/cms/index.php/inhalte/item/{preg_match 1}/\/([0-9]{1,2})\.([0-9]{1,2})$/{preg_match}-{preg_match 2}/\/([0-9]{1,2})\.([0-9]{1,2})$/{preg_match}
Using the internale redirect (another Enterprise feature) you can hide the destination URL from the web browser.
Best regards,
Luigi