WebADI to import and update project workplan structure

Hello,

My requirement is to i) export to csv and ii) manually import / update workplan information (mainly task dates and physical percent complete) to project management module through WebADI template. The export part is done by clicking the Export button against workplan thereby creating a csv file in the local machine. But in order to import I am thinking to use a custom WebADI and a custom integrator for this.

How to update task information through a custom WebADI in this case with all the task columns like scheduled dates, physical percent complete? Do you have any document with step by step and API details.