Bibtexkeys like abc+18 globally changing to abc.18

bibtexkeys generated with [authshort][shortyear] have the + in it for more then three authors. I would like to change the plus to dot for the reason that the plus is not accepted when I export to docbook. A general search and replace in certain fields was possible for version 4, but I cannot find it in version 5. Has this feature been removed or where can I find it?

I found it and it works as expected.