Customise transaction log

I am trying to create a load test report that contains all of the data in the loadui transaction log such as timestamp, trigger timestamp, timetaken, etc but also add in some of the data that is held in the xml request. Whilst the whole message is stored in log i only want certain fields in this case I want to save the value "tracking number" field and have this this as a column before the rest of the log data . The ability to Customise the transaction log would be a very useful feature.