Enhancement CK53N

Hi experts,

I have the following issue. I've been asked to modify tx. CK53N. What I have to do is to change : Depending on material's BKLAS, if this field is 7900, the product costing should change from its level to the "father's" level.

I mean, I have material: M1, this material has anoteher one depending M11, and this one has another one M111. Material M111 has BKLAS = 7900.

Product consting from M111 must appear in "Cost component" at M1 level.

Is there any enhancement or user exit so that I can change include LCKDIF22 before calling module function K_KKB_PC_REPORT_CALL ?

Thanks in avance,

María