Sadly that plugin seems to be broken. Once activated it shuts down all the traffic to my site, seems to be broken.
I have a problem with 404 posts and sadly was not able to find a working plugin that would handle he problem with one general setting, supporting $S.
The probem is that I only need to forward certain subfolders of the old html page.
The syntax of its links were:
Now the URL should be:
The bold part will always be exactly the same and not interefering with any wordpress permalinks, so I think it should somehow be possible to redirect the paths with some kind of wildcard like $S through wpconfig or htacess.
something like Page/Topic/$S = Archive/Page/Topic/$S