If you don't mind having to create a filter with parts in it for every month/year, then this might work (I've done just 2 months here, 07 and 08):
<$list filter="[removeprefix[201608]addsuffix[.08.2016]] [removeprefix[201607]addsuffix[.07.2016]] +[sort[]]"><$view field="title"/><br/></$list>
If I might suggest, there might be a better way. How are you making the tiddlers now? Whatever mechanism, perhaps it could simultaneously date stamp the caption field (or some other field) with the german date format. Then your filter could be very simple, just selecting which field you wanted to sort on.
Good luck!
Mark