[Bro] filtering types from http-ext-outbound.log

[Ewald Beekman]

My http ext outbound logfile is getting a little to large to work
with and contains information about downloaded jpg's, gif's, etc.
which i am not interested in anyway.

How can i filter out those url's so they don't end up into this
logfile, or if that's complicated, how can i limit logging into
this file to only contain "application/x-dosexec" downloads?

thanks in advance,
Ewald...