Redirect without loosing .html-ending

Hi
Is there a possibility to redirect an url like /example/test.html to http://otherdomain/test.html? If i redirect as it is written in the grav documentary, it always looses the .html... What have I done wrong, how can I fix this?

How did you configure the redirect so I can test/debug???

Thank you for your reply.
Actually I've redirected it like this:

redirects:
  '/stadt/(.*)': 'http://energiestadt.tk/'

so It redirects all to the root directory.
But what I would like to have is that the original /stadt/index.html and /stadt/shoppingmall.html etc is redirected to http://energiestadt.tk/index.html or http://energiestadt.tk/shoppingmall.html etc.
If I do it like this:

redirects:
 '/stadt/*': 'http://energiestadt.tk/$1'

It redirects /stadt/shoppingmall.html to http://energiestadt.tk/shoppingmall instead of http://energiestadt.tk/shoppingmall.html

Ok turns out this was a bug.. fixed in Develop: https://github.com/getgrav/grav/commit/afc18236c2d43907b96577272dff517ddc037640

Ok, thanks for fixing it. When will this be in the master / normal branch?