Need ABAP code

Hi Experts,

I am looking for ABAP code for below logic kindly help me

CKIS- KALNR = IMAV- KALNR

Go to CKIS table get cost estimation number(S) CKIS- KALNR.

Get the transfer cost estimate number(S) CKIS- UKALN and INSERT again

in CKIS- KALNR to get WERTN and STEAS.

Club all the line items by KALNR and sum it up by WERTN.

Thanks,

Das.