Populate BO Data - Freight Order

Hello BOPF Masters,

I'm just starting with BOPF developments and I would like some help if possible.

I added some fields in the standard screen, and now I need to populate the data from another BO. The Information is the 'planning date' of freight order on the schedule line tab.

I also need to populate the fields entering the freight unit of BO.

If someone could guide me throught the necessary methods to get these informations or have some material that could share with me. I would be very grateful.

Many thanks.

Regards