Need to upload Infotype 0014/0015 with cost assignment

Hi,

I used 'HR_INFOTYPE_OPERATION' to upload infotype 0014 and 0015. Now I need to add the cost assignment component, but don't really know how to do it. I understand the cost assignemnt elements are stored in the ASSHR and ASSOB tables, but try to avoid update the table directly. What is the correct way to upload IT0014/0015 along with cost assignment? HELP!!!

Anna Tang