Pricing in invoice from delivery

Hello Experts,

My requirement is I have a condition type ZFKO at header level in delivery having a value 100.

When I create Invoice from Delivery if there are 2 items item no 10 and item no 20 the above value should split based on the net value.

at the moment ZFKO and 100 is copied to both the items. so How could I split this in invoice at the item level.

I have tried looking at VTFL but couldn't find right copy control or don't know which copy control to use.

Please advise.

Thanks