Discount in Purchase order using landed cost

Hi,

There is a need to gives discount in Purchase order which we have enabled using landed cost. To account this we have created new G/L class and setup has been done for DMAAI 4385 and 4390 but in F43121, VANI fields is getting populated as blank for this discount LC line. For all other lines like base and other LC lines is populating data. Can any one help where need to do setup so that it's gets populated in VANI of F43121 for this new G/L class.

Regards,