Get variantclass from KMAT in report

Hello Community,

I want to program a "F4-valuelist-function" in my zreport where the user can find

all dependent characteristics from the variantclass (type 300) of the

KMAT. The KMAT is the select-option in my report. So the program

should find the right class and then use a bapi to list all characteristics,

so the user could choose the chosen characteristic for his request.

I can't find the association between KMAT (MARA) and CLASS in SAP.

Can anybody guide me?

Thanks

Markus Pawlinka