Customer from Project

In time-sheet I also would like on the report to pull the customer linked to the project from the timesheetdetail.

How can include that column on the report builder?

You may have to add a custom field on your DocType and use custom script for the same to populate customer. Here is a link you may find useful.

ohhh well I am not that good into that… do you know about an example that I could use?