You could use something like this:
=aggr(if(index(Concat(Group,';'), '10')=0,Name), Name)
However, it looks for every instance of 10 so if you have a group called 110 it would filter out that name too
(you can cirumvent this by concatenating start and end characters to the Group field in the Concat() function.)
My new attempt was to add a chart and within that chart use a calculated column (min (Group) ) . This will for each name show if a name is in an group 10 (from my example) Only john is in group '10' . by selection 'the rest' i have my query result....
In my example this 10 could be extracted because it was the lowest; in other cases your example would do Johannes.
I did find the usefull informaion via your reply on the aggr function via http://community.qlik.com/message/70711#70711
Difficult solution to eliminate all accurances of a name if a name is 'In an group' .