variant Configuration

Hi Experts

iam working on Variant Configuration i developed a function module

but it is not giving correct answer in my custom function module i use 2 standatd function modules i think error is in those Fm.

can any one tel the similar function modules or bapis for this

CUKD_GET_XREF.

CUKD_XREF_OBJ_CHARC

plz reply me if there is any Fm or BAPI's similar to those