Modifying Report Design > Logs (Columns in Log report)

Hi,

I have been trying to edit/modify the Logs report format in the "Report Design > Logs" section. I need to do so in order to have an output form which better suit our company requirements. 

I have been able to modify the header and title sections of the Log report, however currently I am struggling to modify various columns of the log report form. I understand that I have to connect each log report column with the corresponding table through a code to update it accordingly. However the code line required to to do is not clear to me. 

I shall be thankful if someone can guide me to the relevant help/tutorial file explaining how to modify the Log Report columns. If such document does not exist, then even a couple of simple examples demonstrating the linkages between log report columns and relevant tables would give me a reasonable head-start to do some self-learning.

Thanks in advance.

Irfan