Thanks Alan. I'd prefer to avoid postprocessing. I've came up with solution in ulang: if (!Framed-Compression) { update control { line == "%{Framed-Compression}" } } else { update control { line == ""%{Framed-Compression}"" } } if (!User-Name) { update control { line == "%{control:line},%{User-Name}" } } else { update control { line == "%{control:line},\%{control:empty}%{User-Name}" } } And then I can use line variable in linelog module :) But also I'd like to write a header to that csv file so I quess I'd end up in writing custom module in perl or C. thanks, Chris