You can create your own columnizers and use them with LogExpert.
Have a look at www.log-expert.de/sdk.html. There you can find instructions on how to build your own columnizers and some example code.
1. You have to provide a DLL written in some .NET language.
2. You have to implement the ILogLineColumnizer interface exported by the ColumnizerLib DLL.
3. Put the DLL into a subdirectory of LogExpert called 'plugins'