When nothing else helps - you can alter source code of EurekaLog. Of course, it's possible only if you have edition with full source code (all other methods of customizations listed previously are applicable for any edition of EurekaLog).
You can alter EurekaLog code to absolutely every behavior that you want. Then you need to recompile it for these changes to take effect. See also: how to recompile EurekaLog.
Please note that any upgrading or reinstalling EurekaLog will overwrite EurekaLog files, thus your customizations will be lost (unless you made a backup). You'll have to re-implement all customizations each time you upgrade EurekaLog. For this reason use this method as last resort measure only. Prefer the above discussed methods whenever possible. If you still has to modify EurekaLog sources - please, let us know why you do that. We can add your customizations in EurekaLog, so you won't need to re-insert them into source code each time you upgrade (of course, this is only possible if your customizations has some value for other developers).