[texhax] makeindex sorting

[Benjamin Sambale]

Dear forum,

I have the following problem using makeindex:

If I write

\index{aa}
\index{aB}

I get the (in my opinion) right sorting

aa
aB

However I want some entries for symbols. So I write

\index{*a at a}
\index{*B at B}

But then the sorting is the other way around:

B
a

How can I achieve the "right" behavior? Of course I can change 
\index{*B at B} to \index{*b at B}, but there are a lot of such entries and in 
some sense information gets lost doing this. Another chance would be to 
use xindy, but I'm not sure if it is possible to do such things in xindy 
and moreover I don't want the change the whole document.

Thanks,
Benjamin