SAP IBP supply mapping of KF

Hi IBP experts,

I am facing challenge for Supply Planning in SAP IBP.

I am working on some custom KF.

I already mapped the demand data with Independent Demand, and other KF with standard KF like initial inventory.

But I have a custom KF which is sum of Open purchase Order and Inventory called KFTOTAL.

Now unable to map this custom KF with standard input KF require for supply.

Could  anyone suggest also with which KF I will map this custom one so that I am able to run the supply plan.

Also to mention that i am trying to load custom kf data into standard kf .

Regards,

Suprio..